Artistic Theme

It is important to have a cohesive visual theme for the game. Each piece of art will be reviewed by the art department lead and provide acceptance and feedback to the artists. Below are topics of discussion that effects the art department and the artistic theme of the game.

Culture, History, and Realism

The visual designs of the art in the game should hint at a deeper culture than simply what is seen on the surface. It is important that each of the civilizations have a sense of culture and history; that they have and truly did exist outside of the context of the game. The tools, homes and armor of a race should match the unique gameplay that the civilization offers.

An example: the Iberians (native to the peninsula of Iberia, modern day Spain and Portugal). They are fierce defenders of their homeland. Strength does not lie in numbers but in the skilled tactics of guerilla warfare. The weapons given to a unit are therefore numerous and versatile. Units often serve a dual purpose role and are equipped as such. Their amour and garments are practical with colors alluding to their ability to camouflage with their surroundings. Their buildings are strong and practically built.

History and its usage in the game are paramount. When in doubt ask a WFG historian.

Realism is always an interesting topic of discussion. Realism, while important does take a back seat to a more important player – Gameplay. Gameplay trumps Realism when the two topics disagree. Realism might dictate that a phalanx formation included over 500 soldiers, but gameplay only allows so many units on the screen at one time – not to mention the serious pathfinding and control issues so many units in the game would cause. Therefore gameplay dictates that we limit the formation to 20 or so units. Numerous examples such as this may be found in the game design discussions. We are creating a game after all, not a simulation.

Exaggeration

This, at first may seem in direct contraction to our attempt to attain realism, and that may be true. Although all the entities in the game should be based in reality that does not mean that you should disregard exaggeration. These figures featured in the game are many times larger than life. Exaggeration in the game can best be described as a heightened sense of reality.

Phases

The game does not advance through Ages (like the Age of Empire series games), but rather phases of growth. In the interests of reducing art workload, building models are not replaced with upgraded versions when a player advances from one phase to another. Therefore only one set of structure models is needed per civilization.

Citizen Soldiers

Citizen soldiers are entities (units) that change appearance as they are played in the game. They upgrade based on combat experience. Their appearance changes when this upgrade is complete. Here is the general guide for appearance based on a unit’s rank:

  • BASIC: Economy focused, light to little or no armor
  • ADVANCED: Light trooper, lower/middle classed soldier, with moderate arms
  • ULTIMATE / ELITE: Veteran warrior, the elite status. They possess the best weapons and the best armor.

Player Color

Colors on the units should be neutral (skin tones, browns, grays, golds, bronze, etc...), because bright and saturated color will be used as a player’s color to show ownership. Player color usually is found on decorative elements of a texture. Learn more about how to create player color in the texture and skin section of this document.

Building Shape Consistency

It is important to have the building types of civilizations be roughly the same shapes for easy recognition by the players across civilizations. You will always know that a building is of a certain type because they all have some feature in common. Usually it is they way the buildings are laid out, but we also use size to make distinctions.

0 A.D. Theme

  • Above average color saturation (compared to the real world)
  • Contrasting - shadows and highlights within textures
  • Relatively realistic in terms of world/nature and history
  • Humans arent true to the real world in scale, but exaggerated to look like humans at greater distances. Men are burly and broad shouldered, and women are very… womanly.
  • Exaggerate the animations - like theatre but not to the point of silliness. We need to make sure players know what actions they are doing.
  • Exaggerate the traits of the Civs - Celts were colorful (so in the game they will be very colorful) - Greeks had fancy architecture (so many of their buildings will be fancier than in real life), etc...

Art Pipeline

The following diagram displays the basic flow of art pipeline as content is created for the game. It starts up in the top left and is completed at the bottom right. The remainder of this document will be used to describe these processes in more detail. This section’s intent however is to provide you with a brief overview.

http://www.wildfiregames.com/0ad/images/artspec/image002.gif

  1. Design Document

The design document dictates the design of the game. Game designers have pooled their efforts with the game’s historians to create a written description for every entity in the game. This written design concept is created with the purpose of directing the concept artist. The written design concept might refer to reference images to aid in visually describing the entity.

  1. Concept - Next, the written concept goes to the concept designers for their first draft. As with some things in the Art Department, there is no set limit to the number of revisions a concept designer will do to ‘get it right’. It is a hit or miss process guided by feedback from the lead until you get close or nail it on the head. Once a concept is deemed complete for the character, a front and side character design should be rendered to aid the modelers and textures.
  2. Modeling - Based on the concept or written description, a 3D model is then made fitting the concept as close as possible within the restraints of the modeling specifications found later in this document. The modeling process also includes unwrapping and exporting a uvw map for use by the texture artist.
  3. Texture - A skin (or texture) for the 3D model is then created. This may be created from scratch, using reference textures, or even utilizing the concept to make the best possible texture. Close attention is made to the texture to give it a worn and used appearance. Artificial shadows are created on the texture to fill in the details that a low poly mesh is not capable of doing. In some cases player color or transparency is used on the texture. In this case the alpha channel utilized to accomplish this. More details to follow later in the document.
  4. Rigging/Animation? - Non-static models require rigging and animation. This is a complex process that is discussed in more detail in the Animation section.
  5. Export - Finally, the models and textures need to be exported and implemented into the game engine. TGA and BMP files are converted to DDS files (if not already exported as a DDS). DAE files are exported to the /mesh and /animation folders.
  6. Actor - Actor files are an XML file that defines the visual properties of an entity in the game. These actor files in essence are the glue that puts parts together. The file points and references the mesh, texture, and animations of a unit. They also specify object color, player color, and shadow properties. Any mesh or animation created won’t be recognized by the game engine unless it is referenced by an actor XML file.

Concepts

Concepts are largely done for the game, this remains as a reference for future patches/versions and contains some useful information in general.

Concepts are very important to designing a game. One large reason is that we can all view the collective ‘vision’ behind the artwork in the game before it goes through entire art pipeline. This gives it all a sense of collectiveness. After-all this is one game and not a hodge-podge of artistic styles that very from individual to individual.

Concepts are the foundation of the rest of the artwork that we will be doing for the game. What is created by the concept artists will move down the ‘assembly’ line to the modelers and skinners.

Refer often to the civilization design documents:

The historical reference site here is also useful: http://www.wildfiregames.com/users/art/history/

Here are key points to address for concepts:

· Look - Black and white images (later colored if there is a specific point of detail that can’t be described with simply words)

· Title Block - http://www.wildfiregames.com/users/art/titleblock.jpg . Top box is the name, version in the middle left, and date on the right, your name at the bottom.

· Descriptions – feel free to draw arrows and write text in the image for anything you want to draw attention too

· Auxiliary view - If there is something to relate to the modelers that you couldn’t capture in one view, feel free to sketch a picture to the side from another angle.

· Citizen Soldiers – If it is a unit that upgrades (basic, advanced, elite) then three sketches are required.

· Backup – Back up all your work in the art SVN in case something bad happens to your computer – compressed please (ZIP, RAR)

These are great examples of some good concept art created for 0 A.D.

The (Ultimate – the highest ranked of this citizen soldier type) Roman Triarius was drawn by Brenden Keough. Note how he drew two different views of the unit so that there isn’t any question of what certain features that would otherwise be missed by the texture artist (like the greeves that only go halfway around the shin, and the extra detail seen in the helmet. This unit also has a few props included with the concept to ensure that they are represented with this unit as well. The other great thing about this concept is the detail. There is so much detail that it could actually be cut and pasted directly into a unit texture.

The civil center is another fine example of a concept created by Michael Hafer. Now this concept didn’t need to be colored because he so accurately described various features with notes. This is perfectly acceptable and actually preferred because it is a much quicker process than coloring an entire concept. Note also his overhead image in the lower right hand corner to help show exactly where the building are positioned about the complex structure.

http://www.wildfiregames.com/0ad/images/artspec/image003.jpg

http://www.wildfiregames.com/0ad/images/artspec/image004.jpg


Models

Models are the next stage. Models are pretty important because they form the shape of the characters in our game world. The key to our models (because this is a full 3d game) is to rely on our skins for the details of the objects in the world and not the geometry. The industry buzz word for this is ‘low poly’. We will try to keep our polygon (tri) count down as low as possible. We can do to this by taking advantage of the opacity maps, removing polygons nobody will ever see (bottom polys), and relying on the skin for detail.

Here is what we're looking for in models:

  • Poly counts - as low as possible! Here are the suggestions:
    Humanoid Bodies – 500
    Animal Bodies – 700
    Humanoid and Building Props – 50
    World Objects – 150
    Buildings – 800
  • Unwrapping - Unwrap your own 3d models as best you can – they can be tweaked by the skinner later, but don’t force the skinners to do your job for you.
  • Formats – *.blend, *.max or *.3ds is preferred in a zipped file. Final approved file will be exported as a *.dae (COLLADA).
  • Scale – See the http://www.wildfiregames.com/forum/index.php?showtopic=793. Builidngs/trees are about 2/3rds the scale of humans. Props should match the scale of humans.
  • Joints – if you unit is going to be animated, make sure there is enough vertexes around the joint to bend with minimal distortion.
  • Think Ahead! – Try to imagine how you would skin the model and use opacity maps where you can.
  • Backup – And if you have access to it backup all your work in the art SVN in case something bad happens to your computer – compressed please (ZIP or RAR).

3D Tools

Blender 2.6 (and above) and 3D Studio Max (release 6.0 and above) are the recommended 3D model and animation packages used for the Pyrogenesis Engine. The game now supports COLLADA’s DAE files which allow users to create content in a variety of software programs. Older pyrogenesis models in the game are defined by custom file formats PMD (Pyrogenesis Model Data) and PSA (Pyrogenesis Animation). See Appendix A and B for more details describing these formats. The development pipeline previously used a custom export 3d Studio Max plug-in that exported files in PMD and PSA formats.

Recommended 3D software options:

Blender

Maya (using ColladaMaya)

3D Studio Max (using ColladaMax)

Softimage|XSI

MeshLab

SketchUp


COLLADA Export

A variety of 3D programs can export models in the Collada DAE format

General

  • The animation should be 30fps. The first and last frames of the animation should be identical. The animation should play at the speed you would expect to use in the game.
  • Any object attached directly to the skeleton will be treated as a prop point. If you want to add extra objects for testing the animation, link them to the existing prop points instead of to the skeleton.
  • Meshes must be made of triangles.
  • There may be some issues with scaling and rotating the skeleton - please provide any relevant information you find about problems or solutions.
  • Prop points should be defined by creating an object (e.g. a Dummy helper in 3ds Max) named prop-whatever, where the whatever is the name of the prop point. The file data/tools/atlas/lists.xml lists the standard prop attachment points. That object should then be attached to a bone.

Blender

http://i.imgur.com/SNzTJ.jpg

Collada models exported using Blender 2.6+ are now mostly compatible with 0 A.D. as long as a few simple rules are followed. If using earlier versions of Blender you may find exported collada files produce errors in-game, so we recommend Blender 2.6+ when creating models and animations for 0AD.


Exporting Collada models to use in 0 A.D.

After creating your model, select it in object mode and go to File > Export > COLLADA (.dae). Then click the 'Export COLLADA' button after giving the .dae file a name and selecting the export directory. That's it, hopefully a 0AD compatible model/animation file has been saved.

Generally following these rules will help the collada files open in 0 A.D. -

1) You should only export 1 object per collada model. If your file has multiple objects, select only 1 for export and activate the 'Export only selected' option in the Collada Exporter options panel.
2) Your mesh should be UV mapped. A simple unwrap can be done by selecting all faces in edit mode and going to Mesh > UV Unwrap... > Unwrap
3) Your object should only have 1 material, otherwise the model will not import. Delete unnecessary materials using the Material tab while the object is selected in Object mode.

For a more detailed step-by-step tutorial showing how to create a new object for use in 0 A.D., view the Basic 3D Implementation Guide


Importing collada models from 0 A.D. into Blender
If a collada model doesn't import into Blender try the following:

1) Open the DAE file in Notepad
2) Find the line <diffuse>
3) Delete the entire <diffuse> element. It'll look something like this:

<diffuse>
<texture texture="Map__123-image" texcoord="CHANNEL0">
<extra>
<technique profile="MAYA">
<wrapU sid="wrapU0">TRUE</wrapU>
<wrapV sid="wrapV0">TRUE</wrapV>
<blend_mode>ADD</blend_mode>
</technique>
</extra>
</texture>
</diffuse>

(Delete everything from <diffuse> to </diffuse>)
4) Save the file (don't change the DAE format)
5) Try to import it again

If the above fix doesn't help, it's possible the Blender importer will be unable to import the model. This could be because the model has skeletal animations or other incompatible features.


Useful 0 A.D. Blender links


pmd2collada - Converter by Matt Minton - Use to convert Pyrogenesis PMD format 3D models to the Blender compatible DAE Collada format. Currently only works with static models.
Collada fixscript - Python script that fixes Collada static models for use in Blender 2.5x


3ds Max

  • Download and install ColladaMax, from our site (version 3.02). Requires 3ds Max 9, 8, or 7 SP1.
  • Open/create a model in Max. If it is a skeletal model, it should have our standard structure and be named Bip01.
  • If there is more than one mesh in the scene, you need to indicate which one should be exported:
    • Either: select one of the meshes, then do File -> Export Selected (and remember to select the right mesh each time you export);
    • or open the Properties dialog for one of the meshes, and set the User Defined Properties to export, and then do File -> Export. The other meshes will still be exported, but ignored when loaded into the game.
  • When selecting the filename to export, specify the lowercase extension .dae. The default is uppercase, which won't work.
  • Place the file into the game in the same way as you would with PMD or PSA files (in the /meshes and /animations directories, respectively).
  • Actors can point to the .dae file as a mesh or animation, and the game will load them automatically. If there are problems while loading, the game's log file (OpenLogsFolder.bat -> mainlog.html) should say what was going on.

Sketchup

Note: This has only been used to export files from Sketchup and import them into Blender. This should work for other programs.

  • Share file to the 3D Warehouse. You will require a Google Account.
  • Search your user name on the 3D warehouse using a browser (Not using Sketchup).
  • Click on download and download the Collada ZIP file.
  • Unzip the ZIP file. The DAE file is located under the "Models" folder.

There is, possibly, another way to do this.

XSI

  • Use XSI 6.0.
  • For skeletal models/animations:
    • Rename the skeleton to Biped (so the root object is called Biped_GlobalSRT), so the game knows what skeleton structure to use.
  • Export with File -> Crosswalk -> Export -> Format = COLLADA 1.4.1.
  • Enable Export XSI Normals. Enable Convert Geometry to Triangles if the mesh is not already triangles.

PYROGENESIS IMPORT/EXPORT

This plug-in is only tested to work on 3ds Max Release 6, WFG used this tool and format before COLLADA.

You may download from here:
http://www.wildfiregames.com/users/art/pmdexp6.rar

Essentially this tool allows users to export PMD (Pyrogenesis Model Data) and PSA (Pyrogenesis Animation) files directly from 3ds Max R6. This process skips the exporting of a DAE (COLLADA) file that is later converted to a PMD or PSA file in the future. This method is not preferred. The tool is broken in that it does not blend weighted vertexes in animation, it also only allows biped/physique methods to animation (bones/skin do not work).

  1. Function: Creates Prop points
    Access: In the Command Panel - Create => Helpers => PS Helpers => Prop Point
    Extra: Export with the .pmd file, modify the name as desired, but precede with “prop-“, example prop-r_hip
  1. Function: Export .pmd files
    Access: File => Export or File => Export Selected
    Extra: Select mesh and any props and export
    Dont forget to save the file in all lower case
  1. Function: Export .psa files
    Access: File => Export or File => Export Selected
    Extra: Select the bip node and export
    Dont forget to save the file in all lower case

Currently you must center the mesh to the origin of the world before you export it (X=0, Y=0, Z=0); as it retains its global position when exported from Max, which moves the mesh to some undesired position in the game.

Helpful hints while using the PMD/PSA plug-in and usage in 3ds Max:

  • Save the prop helper with the PMD
  • Dont need to save the prop helper with the PSA
  • Save BHP files to transfer animations to another biped
  • Need to include the hip/bip node in the PSA
  • It matters what bone the prop is attached to when you export the PMD.
  • You dont have to have it in the default pose when you export the PMD.
  • You must NOT be in figure mode when you export the PMD.
  • Mirroring does weird things
  • PSprop Z points up generally
  • PSprop X points right generally
  • PSprop Y points back generally
  • Can put UVW modifier on top of Physique
  • Can modify poly under Physique (triangulation and smoothing groups)
  • Layers of animation work nicely to slightly alter a motion

Other 3DS MAX Plugins

3D Studio Max, while powerful, does have useful additional features/settings that may be added to the default installation and prove to be helpful for creating art content.

Texporter - A useful plug-in by Cuneyt Ozdas, Texporter allows UV maps to be exported from 3DS Max as a bitmap. Then use this template for texturing in Photoshop or similar 2D paint program. Download from http://www.cuneytozdas.com/software/ Install texporter3.dlu in the 3dsmax/plugins folder

MAX2OBJ and OBJ2MAX - These plug-ins were created by Harald A. Blab. They were useful in previous versions of 3ds Max that did not have the functionality of importing and exporting OBJ files. MAX2OBJ generates an Alias|Wavefront OBJ and MTL file from a 3DS Max scene. OBJ2MAX imports Alias|Wavefront OBJ and MTL files into 3DS Max. This version adds new options handling pivot points and OBJ smooth group import. If the importer crashes, do not use normals on import. This is useful for earlier versions of max to communicate with other software programs and retain more detail than a 3DS file is able to. OBJ’s, as mentioned, are capable of retaining smoothing groups.

SCRIPTS – There are a few scripts I’ve included that are useful.

orientator.ms – this script is really useful for props. It allows you to quickly orientate one object to the same orientation as another (matching both position and rotation). For example, you can select a sword, and quickly snap it to the position of the hand prop point helper. Once it is in position you are able to parent it to the point to move with it throughout animation.

rotaterzero.ms – this script quickly zeros out the rotation in x, y, and z. Useful just prior to exporting.

zero.ms - this script quickly zeros out the position in x, y, and z. Useful just prior to exporting.

Clear materials – I haven’t created a script for this, but you can simply paste this into the max command bar and it will remove all the materials of the selection. $*.material=undefined This is useful to export a file and avoid other receiving errors that they are unable to find textures or materials.


Scale and Proportions

Proportions in the game, in general, will not be true to the real world. Humans will take on the proportions of a hero. Animals will be formed with a slightly exaggerated eye. Structures in comparison to units will be roughly ¾ the size (though roughly 7/8 scale is given to windows and doors to aid in the transitional illusion of scale)

Scale is defined as thus: Height of a Man ˜ 2 meters = 4 generic units in 3ds Max = 1 square tile width in Pyrogenesis.

http://www.wildfiregames.com/0ad/images/artspec/image005.gif

Structure footprint scale (in tiles) is as follows:

VILLAGE PHASE STRUCTURES


* 5x5 - Civic Centre (Village Centre=>Town Centre=>City Centre)
* 2x2 - House
* 3x3 - Farmstead
* 3x6 - Field
* 3x6 - Corral
* 3x3 - Mill
* 1x1 - Outpost
* 1x4 - Wall Section
* 1x1 – Tower
* 1x2 - Gate




TOWN PHASE STRUCTURES


* 4x4 - Dock
* 4x4 - Market
* 4x4 - Barracks
* 3x3 – Temple

CITY PHASE STRUCTURES


* 5x5 – Fortress

Polygon Count Limits

Pyrogenesis supports real time strategy games. RTS games have large numbers of entities on the screen at one time at a small scale. Due to this small scale, the total polygon limits are rather low compared to the average first person shooter. This is a list of recommended max poly counts for 3D Modelers to take into account with making 3D models.

Humanoid Bodies – 500
Animal Bodies – 700
Humanoid and Building Props – 50
World Objects – 150
Buildings – 800

Note: Engine DOES NOT support Double-Sided polys - don`t use them. If double sided polys are required, duplicate geometry must be created with the normals flipped.


Level of Detail

Because the models in the game will be small on screen and because the poly counts must be kept low, anything smaller than a human hand should not be modeled but included in texturing.


Orientation

The orientation of models in the game follows standard max views. When viewing from the max Front view it would display the front facing view of the model. In other words, the model should be looking along the negative Y axis.


Props

Pyrogenesis uses a system that is called propping. It is also defined in the computer world as a parent/child or master/slave relationship. In 0 A.D. we call it a body/prop relationship. Props are objects that are separated from the parent and have the ability to be used independently in whatever circumstance deemed fit.

They are ‘attached’ in the actual game by the engine by a designation in an XML file. Every bone in a skeleton is capable of having a prop point attached to it as a child. That prop point is a ‘node’ that can be identified in an XML file and a prop may be assigned to that node. The prop orientates and positions itself to the prop point node in the game. The prop follows the movement (if any) of the bone it was attached to.

The advantage this gives us is versatility and variety. It also cuts down on the downloaded size of the game. Instead of making 200 totally unique units, we simply create 8 basic shared body types, 50 or so props, create unique skins, and create combinations of these basic elements to allow for a host of options to developers and gamers/modders! This proves to be a very versatile system for creating content for the 0 A.D. world. To reiterate, armor and weapons are not to be included in the base mesh of the unit except under very special circumstances (we have yet to see it, but never say never).

Here are some examples of props: helmets, weapons, shields, capes, quivers, pottery, barrels, baskets, vegetation.


Tutorial: Proping with pyrogenesis 3ds max plugin

This tutorial teaches on how to use the Prometheus 3ds Max propping tools. This will enable you to use the propping feature while doing your modding for 0 A.D. Well, if we are going to work with 3ds Max, we are going to need a plug-in and you can download that HERE.

What propping does is allows us to transform this:

http://www.wildfiregames.com/0ad/images/artspec/image006.jpgVS.http://www.wildfiregames.com/0ad/images/artspec/image007.jpg

This is an important tool because in 0 A.D. we only allow one texture per model. We also made an effort to conserve the texture database size by reducing the quality of textures in the game. This also, in the long
run, sped up the development process and encouraged visual cohesion.

So, what is a prop? Well a prop is an actor with its own attributes and behaviours. In this example, here is a a better view of the above images that shows what in the image are props:

http://www.wildfiregames.com/0ad/images/artspec/image008.jpg

We have a crate, barrel, anvil, dummy, shield, windows, door trim, and a chimney. Now, in the game, we can create multiple prop points. This can be useful because you could add variety with a random function that swaps out prop actors with every new entity created in the game. So, for example, with this one, we could have that shield actor switch out with a collection of shield props. However, for the purpose of this tutorial we will consider this collection of props as one prop.

So lets get started!

http://www.wildfiregames.com/0ad/images/artspec/image010.gif

This is how the building looks on our 0 A.D. max file template. You can see the building is properly scaled for a 3x3 tile size and all the props are so far unique actors. Even though the props are separate objects (at the moment), they are sharing the same textures. Again, if a prop has a separate texture, it must be attached separately with its own prop point. Here is the texture that these props are skinned with:

http://www.wildfiregames.com/0ad/images/artspec/image009.jpg

The first thing we want to do is get everything orientated in one common location. The reason being is that each prop is anchored by a prop point. When we export the prop object, its orientation is based off its local axis. So, the idea is - we need the prop objects pre-positioned to ensure proper alignment in the game.

Step 1 - Attaching



The next step is to select the structure and attach all
the props:
http://www.wildfiregames.com/0ad/images/artspec/image011.gif







You will see the following menu pop up, just hit OK.


http://www.wildfiregames.com/0ad/images/artspec/image012.gif
Step 2 - Pivot Placement



Now, all your props will be included in one object. We
next should move our object to the centre of the 3dsmax world. In order to do that we need to make sure our pivot point is in the correct location.

http://www.wildfiregames.com/0ad/images/artspec/image013.gif


Click on the hierarchy tab, then click the pivot button, then the "Affect Pivot Only" button.

http://www.wildfiregames.com/0ad/images/artspec/image014.gif


Centre your pivot (X,Y) to the centre of your structure (or where you want it to be anchored in the game).

http://www.wildfiregames.com/0ad/images/artspec/image015.gif


The Z is a bit different; we want to position this to the bottom of the structure. If we put it in the middle, then your structure would be buried halfway in the game's terrain. Not good.

http://www.wildfiregames.com/0ad/images/artspec/image016.gif


Ok, youre now done moving your pivot. Turn off the Affect Pivot Only button.
Step 3 - Detaching



Now, let's move our structure to the centre of the world. You can do this by just inputting zeros in the world coordinates at the bottom of the screen.

http://www.wildfiregames.com/0ad/images/artspec/image017.gif


http://www.wildfiregames.com/0ad/images/artspec/image018.gif

The next step is to separate the props again from the object. So first we select all the prop objects like this image to the left.

Then we detach them.

http://www.wildfiregames.com/0ad/images/artspec/image019.gif


A new window will pop up.

http://www.wildfiregames.com/0ad/images/artspec/image020.gif


Im going to go ahead and properly name it right here.

While Im at it, Ill go ahead and properly name the structure too.

http://www.wildfiregames.com/0ad/images/artspec/image021.gif
Step 4 - Setting the Prop Point



Now, it's time to work with the prop point. First, we need to create one.

http://www.wildfiregames.com/0ad/images/artspec/image022.gif


Click on the create tab, then the helper object button,
then scroll down and you will see a choice of PS Helpers. Select that.

http://www.wildfiregames.com/0ad/images/artspec/image023.gif


Now our prop tab looks a bit different. Go ahead and place a prop point. Once you place it, it will look like this:

http://www.wildfiregames.com/0ad/images/artspec/image024.gif
Step 5 - Exporting



It is time to export! select both the prop point and the
structure.

http://www.wildfiregames.com/0ad/images/artspec/image025.gif



Go to File => Export Selected

http://www.wildfiregames.com/0ad/images/artspec/image026.gif



Now go ahead and export your structure.

http://www.wildfiregames.com/0ad/images/artspec/image027.gif



And that's it! You just exported an object with a prop point included! Repeat the same export for the prop point.
Step 6 - xml code



Youre all done in 3dmax. Now it is time to look at the
xml code.

http://www.wildfiregames.com/0ad/images/artspec/image028.gif





In this code snippet:



We have given it the proper name (the name that will appear in Atlas). We are also pointing to the newly created *.pmd file. We call up the texture.

We name the prop point and tell it what actor is supposed to go there.


http://www.wildfiregames.com/0ad/images/artspec/image029.gif




In this code snippet:



We have given it the proper name (that will be called up by the code above). We are also pointing to the newly created PMD file. We call up the texture.



Summary



The tutorial above probably has some unneeded steps, but for the beginner, this is a good way to start. You will find yourself refining your procedures with experience.


Skins and Textures

This is such a critical topic because it is the texture of a skin that really gives the game its ‘look’. 0 A.D.’s theme could be described as a hyper-realistic look. This is a historical game and not a fantasy or futuristic game. Our colors will be slightly more saturated than the real world. We also want to reflect the ‘realness’ of our world by NOT making things look totally new like you just purchased them off a store shelf, but rather: used, weathered, worn, ‘real’. It is very important to follow the concept, do not make creative liberties. The concept has been approved by the art department lead and the historian, your idea in your creative mind has not been. Make sure the viewer always knows what they are looking at. Also, pay particular note to details! The more detail that can be added to a texture, the better.


Here are some key elements of what makes up a good skin:

  • Historical foundations – work with history, don’t create your own history
  • Color – slightly more saturation than the real world
  • Theme – heighten and enhance the purpose of mesh through your skin
  • File Formats – Always save your originals in a lossless layered format (PSD, PSP or equivalent). We will be using PNG files for the majority of all skins, see the TextureFormat guide for more info.
  • Size – Power of 2 (2^n)! must be used for the dimensions of the images. These include 8, 16, 32, 64, 128, 256, and 512. DDS files require this. Both rectangular and square varieties may be used by mixing and matching the widths and heights using the above numbers.
  • 64x64 – unit props
  • 128x128 - typical units
  • 256x256 - hero units
  • 512x512 – structures (shared), and terrain textures

Keep in mind that the size of the texture should reflect the relative size in the game. There is no reason to make a texture for a flower to be 256x256 when in the game it will never been seen up so close to see such detail.

  • Methods – Method 1 (Recommended) - start with a larger original sample, and then shrink. For example, if your target size is 256, then start with a 512 and then shrink by half and sharpen. Method 2 – Some believe that you are creating unnecessary detail and waste time to use Method 1, so they work with the texture at it’s final resolution (most artists are not this good however).

Use Layers! Layers are your friend. Save your layers! You never know when a belt used on one texture might be useful to share with another. Using the texture template you are able to share certain features across textures. If the elements of a texture are separated by layers, this job is much easier.

  • Player color – Player color is achieved through the Alpha Channel of the PNG file. The visual data within the RGB channels should be desaturated (made to black and white). More on this topic further on in this document.
  • Backup – Backup all your work in the art SVN repository in case something bad happens to your computer – compressed your source (uncompressed) files (MAX, PSD, BMP, TGA) please, use ZIP or RAR.
  • Communicate! - If you need help or you would like some links to some good tutorials, feel free to ask questions of your fellow workers and the art department lead.

Preferred 2D Tools

There really isn’t any preferred graphical editing software that is capable of opening and saving BMP files may be used to create textures for Pyrogenesis. Software that is capable of supporting alpha channels and saving files in PNG format would be advantageous (note that Photoshop's default PNG saving mechanism doesn't save the PNGs in a way that the game may use, so for texture files with an Alpha channel please see the TextureFormat guide for how to save the correct kind of PNGs or use another application).

Recommended 2D software options:

Adobe Photoshop – Commercial

Adobe Photoshop Elements – Commercial

Corel Paint Shop Pro – Commercial

Corel Painter – Commercial

Deep Paint 3D- Commercial

GIMP – Open Source, Free

GIMPshop – Open Source, Free

Paint.NET – Open Source, Free

Aviary Suite- Commercial. (Suite will also soon include an audio editor)

DDS plugins:

nVidia 8BF plugin – Free plugin that is useful for software that utilizes 8BF plugins

nVidia’s Developer Tools – Other useful DDS tools


Graphics Formats

. PNG
This is now the preferred image format for all textures. PNG supports lossless data compression and therefore no quality is lost when textures are committed. Alpha channel support allows for PNG files to store additional image data that can then be used in-game. When saving PNG files using Photoshop, we recommend using the SuperPNG plugin

· DDS
Textures are automatically converted from PNG to DDS by the engine to improve loading times. Textures should no longer be in DDS format when committed.

DirectX Texture Compression : DXTC is the native, compressed texture format used in DirectX 9. In many cases, DXTC reduces texture memory usage by 50% or more over palettized, 8-bit textures, allowing for twice the textures at the same resolution, or the same number of textures at twice the resolution. Three DXTC formats are available. You can see a detailed comparison on the different types of texture compression here: http://udn.epicgames.com/pub/Content/TextureComparison/ The color channels are all the same DXT1, DXT3, and DXT5 - in terms of compression and quality. The difference lies in the alpha channel.

· DXT1 is a four-bit compressed color format that allows for opaque, and one-bit alpha (DXT1a) textures; that is, textures with no transparency at all, and textures with a single transparent color.

· DXT3 adds support for a four-bit explicit alpha channel, on top of DXT1's color compression. Four-bit explicit alpha allows for sixteen distinct alpha values, making it good for textures with 'sharply contrasting translucent/opaque areas. DXT2 textures assume the color data is pre-multiplied by the alpha channel.

· DXT5 support a four-bit interpolated alpha channel. Three bits are used to determine explicit alpha values, and two eight-bit values are used to interpolate gradually between them. This makes the format especially suited for soft gradients and other textures where the alpha areas’ variance is mild. DXT4 assumes colors are pre-multiplied by the alpha channel.

· 32-bit RGBA is the obese godfather of textures. While extremely powerful, it's also terribly overweight. It features full 24-bit color, plus an 8-bit alpha channel, but takes up four bytes for every pixel; a 256x256 texture will require 256k of memory.

· JPEG
DO NOT USE THIS FORMAT.


Basic Human Template

A basic human template link can be found below.

The base texture (affectionately named dude) looks like this:

http://www.wildfiregames.com/0ad/images/artspec/image031.jpg

To the left is the base texture was designed to provide the most basic layer of what will be used in the game. Most all of the game unit art is built of this this skin. This is the standard. The upper left portion is the legs, the upper right is the arms. The lower middle is the body.

The texture is tileable. What do we mean by tileable? Well the textures edges match up to aid you in lining up your texture seams.

To the right you is how the texture is broken down by quadrents. Also note that the integers are based on powers of 2. (though 384 is not).

http://www.wildfiregames.com/0ad/images/artspec/image030.jpg

Notice how the following images wrap and tile as you offset them:

http://www.wildfiregames.com/0ad/images/artspec/image032.jpg


Torso tile now centered about the back rather than the Chest.
http://www.wildfiregames.com/0ad/images/artspec/image033.jpg


Here are the arms tiled and rotated 90 degrees to help visualization.

http://www.wildfiregames.com/0ad/images/artspec/image034.jpg


Here are the legs tiled and rotated 90 degrees to help visualization.
http://www.wildfiregames.com/0ad/images/artspec/image035.jpgThe image to the left demonstrates that with a bit of flipping, rotating, and resizing you can position the tile to look like this image to the left. This allows seamless transitions between the torso and legs if needed. After a texture is complete simply retrace your flipping and rotating steps to return to the original.

The goal is to eliminate the seams in our textures and this template will do that.

The texture is designed to make maximum use of the texture space. The negative side of this is that the scale is sometimes disproportionate. If you want to make something on their body that is vertically and horizontally symmetrical, you need to do this. Crop just the lower half (the red section in the quadrent image above). Then resize this layer so that it’s 512x580. See the image to the right.

http://www.wildfiregames.com/0ad/images/artspec/image036.jpg



Here are more resources:

http://www.wildfiregames.com/users/art/wijit/dude.rar
http://www.wildfiregames.com/users/art/wijit/dude_accesory.rar

In the dude accessories youll find a few examples of some things:

  • necklines that line up
  • sleeveless template
  • sleeve template
  • sample boots
  • sample belt
  • sample shirt
  • sample pants
  • circle representation
  • sample bracers


http://www.wildfiregames.com/0ad/images/artspec/image037.jpg

It is advantageous to use the template in a paper doll fashion. Each of these steps is a layer. The artist starts with the base, next the tunic is added. Then add the breastplate, then the leather loin protectors, and finally the weapon strap. Because these are independent layers, they can be used on other models as well. Note that the color of the tunic is grayscale, this is because it is used as player color; more on that in the next topic.


Player Color

http://www.wildfiregames.com/0ad/images/artspec/image038.jpg

Player color is a special attribute of the game to serve the purpose of showing player ownership. It uses the alpha channel of a texture to apply a multiplied color layer (defined by the game, and player) in real time during the game.

http://www.wildfiregames.com/0ad/images/artspec/image042.jpg

http://www.wildfiregames.com/0ad/images/artspec/image041.jpg

Notice how the player color depth is brought out by the color multiplication in comparing the two images on the left.

http://www.wildfiregames.com/0ad/images/artspec/image039.jpg

http://www.wildfiregames.com/0ad/images/artspec/image040.jpg

These images show how the engine uses the player color to change between various colors.


Object Color

http://www.wildfiregames.com/0ad/images/artspec/image044.jpg

Object color is much the same as player color. It’s purpose is to offer a variety of color other than player color. For example, by using one single texture one is able to create a human head texture with a variety of hair colors: blonde, dirty blond, brown, gray, and black. Horse pelts also use this feature. We are able to use one texture for this purpose rather than multiple which saves space and texture memory for the game. It is designated specifically in the Actor XML file.

http://www.wildfiregames.com/0ad/images/artspec/image043.jpg


Transparency

Transparency, like player color and object color, uses the alpha channel for it’s definition. The same methods are used for creation. This is probably the usage of the alpha channel that most are familiar with, so it doesn’t require much explanation. The Actor file that uses the texture must however tell the engine the texture has transparency and is called out as such in the Actor file.


Other

UV Coordinates and Texturing

Pyrogenesis supports only one (1) UVW channel and Material per object. Only UVW Channel 1 will be used by the exporter and game engine. Multi-sub object texturing should not be used and is not supported. Objects should be textured with just one material.

Original Files

It is recommended that textures created in Photoshop, Paintshop Pro, or Gimp (etc.) are saved as Photoshop Documents PSD files, with their layer information intact, so that later revisions can be made. This will also serve as an easier way to make variations and modifications in the future.

Texture Size

256x256 for heroes

128x128 for citizen soldiers

64x64 for props

512x512 for shared structure textures and terrain textures

Some find that working at double the intended game resolution size in your 2D software package then scaling the final version down is useful. Others say that you waste time creating unused detail. The decision will be yours to make.

Terrain Textures

Terrains must tile. Meaning the left<=>right and top<=>bottom must seamlessly tile with each other. Terrain textures are in a large size because they are such a huge portion of what is visible on the screen. Care should be taken to avoid distinguishable repeating patterns on textures that have a high likely hood of more than 50% of the texturing being seen on the screen at a time (grass, dirt, sand, etc...). Recognizing repeating textures in unique aspects of terrain (cliff, rocks, roads, etc....) are not as critical. A texture spans approximately 11x11 tiles in the game. Scale your details on the texture accordingly.

http://www.wildfiregames.com/0ad/images/artspec/image045.jpg

This terrain texture is for a guide for shadows. If there is a feature on the terrain (such as a rock, or a stick) that would benefit from a shadow, place the shadow to the left of that feature (not the shadow on the blue ball). This would be in line with the shadow position for the default angle and location of the sun in the game world.

Terrain Blends

http://www.wildfiregames.com/0ad/images/artspec/image046.jpg

This image is an example of how textures blend together in our game. There is a calculation performed by the game engine that recognizes the primary and secondary texture adjacent to tile in question itself. Based on that information it applies a suitable alpha mask. There are eleven possible different options. This template was created to help one see those options and create more transitions based on it.

http://www.wildfiregames.com/0ad/images/artspec/image047.gif

To use this image, you are free to modify any part of the blend aside from the pixels on the edges of the grid. It could be a simple gradient as is seen here or it could be made blotchy, or feathered. Remember that the blends must interface with one another so their border blends should match.

Skybox Textures

A skybox is an interesting graphical feature of the world. It is for the most part unimportant to the game, but goes a long way to beautifying the world. The skybox is just that. It is a large cube in the game world that does not move relative to the camera. It is comprised of five textures for all faces excluding the bottom. The textures location is: art\textures\skies\<name>. The five textures are named front, back, left, right, and top. The files are saved as 32 bit RBGA DDS files. Reason being is that there is no file compression which means there are no artifacts on the textures. The textures were created in 3DS max by setting up a 5 camera’s each facing a direction. A textured halved sphere was created. All five camera’s render an image. You can test your images in this small program:

http://www.wildfiregames.com/users/art/skyboxtexturetest.rar

Water Textures

Water textures use normal mapping. They are a series of 60 images that are displayed one after another to give the illusion that water is moving. The movement is simply by the design of the texture. The textures were created by a 3rd party texture generating program. Once they were rendered in black and white they were used as a ‘height map’ and processed by NVIDIA’s DDS Photoshop plug-in to apply the normal map’s color code information to them.


Animation

Animations are typically created by two means either key framing or importing motion capture files. Because all our humanoid characters will be sharing the same proportions and skeleton we will be able to assign common and shared animations to human. The goal is to build up a library of animations, just like a library of props and we will just ‘play’ the animations as defined in the actor xml file in real time throughout the game.

Here is what we are looking for in animations:

  • Exaggerate – your character is very small on the screen. Make sure the gamer knows the difference between swinging a sword and waving hello.
  • Starts and Stops – The animation must be played in cycles and they loop. The pose you start the animation with must be identical to the last frame (except for death animations). Your starting pose should also be the same or similar to those animations of the same type and class. This is to ensure the transition from a standing, to a fidget, to a walk, or an attack will appear seamless.
  • File Formats: Save your original files. All animations will be exported with the COLLADA plugin for the game.
  • Backup – Backup all your work in the WFG art SVN in case something bad happens to your computer – compressed please (ZIP or RAR)

The key animation types are as follows:

Idle – a very subtitle movement simply to let the user know the unit is not a stone.

Attack – if capable of attacking, 2-3 variations would be nice

Walk – a simple walk cycle

Run – if capable, a run cycle

Death – when the unit’s hit points reach zero, the unit must die. 2-3 variations

Foraging – if capable, two types: picking berry bushes, and picking fruit from trees

Mining – if capable, swinging a pick axe

Logging – if capable, swinging an axe

Farming – if capable, swinging a hoe


Tools

Discreet's Character Studio has been the primary character animation tool for character animation. However with the use of COLLADA to export animations, a variety of software packages may be used as long as the skeleton, mesh, and animation use the same scale and bones. Standard 3DS Max Bones may also be used when a custom rig is necessary, though the total number of bones in a rig must not exceed 25.

http://www.wildfiregames.com/0ad/images/artspec/image048.jpg

Above is the image of the hierarchy and naming convention of the basic Biped that is used for all humanoid animation in the game (Note: ignore the green boxes and the footsteps). If an alternative is desired that does not match this structure, contact the developers for support.

Rigging <need to fill out> Bone/Biped? StructuresBones/Biped Limits <need to fill out> Character Animation <need to fill out> Animation Frame Rates <need to fill out> PASAP Animation List <need to fill out> Non Essential Animation List <need to fill out>


Folder Structure

DATA
+MODS
+PUBLIC or INTERNAL (substructure is the same)
+ART
¦ACTORS
¦ ¦FAUNA
¦ ¦FLORA
¦ ¦GEOLOGY
¦ ¦PROPS
¦ ¦ ¦FAUNA
¦ ¦ ¦FLORA
¦ ¦ ¦GEOLOGY
¦ ¦ ¦STRUCTURES
¦ ¦ ¦TEMP
¦ ¦ +UNITS
¦ ¦STRUCTURES
¦ ¦TEMP
¦ +UNITS
¦ANIMATION
¦ ¦BIPED
¦ ¦GAIA
¦ ¦MECHANICAL
¦ ¦QUADRAPED
¦ +SIMPLE
¦MATERIALS
¦MESHES
¦ ¦GAIA
¦ ¦PROPS
¦ ¦SKELETAL
¦ ¦STRUCTURAL
¦ ¦TEMP
¦ +TEST
¦SKELETONS
+TEXTURES
¦ANIMATED
¦CURSORS
¦PARTICLES
¦SKIES
¦SKINS
¦ ¦GAIA
¦ ¦PROPS
¦ ¦SKELETAL
¦ ¦STRUCTURAL
¦ ¦TEMP
¦ +TEST
¦TERRAIN
¦ ¦ALPHAMAPS
¦ +TYPES
+UI


File Naming Conventions

All filenames should follow the naming conventions described below.

General Rules

  • No spaces in the file name are allowed
  • No capital letters are allowed
  • XML, PMD, PSA, DDS files should use these rules. For any file-formats not specially mentioned here, follow similar naming rules to fit the file type.
  • If using numbers always use two digits. Example: 01, not 1
  • Use underscore ( _ ) to separate portions of the file name
  • Use this order <general>_<civ>_<type>_<extra>_<variation>
  • If the folder path to the file already defines one portion of the name, exclude that from the file name.

Examples:

celt_isw_a_01.dds – Meaning: Advanced Celtic Infantry Swordsman, Variation 01 Texture

kart_hc.pmd – Meaning: Carthaginian Health Center Model

General

ui - User Interface

prop - prop

wrld – world


If none of the above, do not use


Civ

rome - roman

hele - hellenes

celt - celt

pers - persian

kart - carthaginians

iber - iberians

brit - britons

gaul - gallic

pole - poleis

mace - macedonians


Extra

b - basic

a - advanced

e - elite

f - fall

s - summer

p - spring

w - winter

#- numbers

etc...
Type

Buildings

cc - civilization center

ho - house

fc - farm center

fv - farm - vegetation

fa - corral - animal

rc - resource center

tf - free standing tower - scout tower

wc - wall

wg - wall gate

wt - wall tower

pc - port center

mc - military center

tc - trade center

hc - health center

ff - fortress

sb - special building

Units

isw - infantry swordsman

isp - infantry spearman

ijv - infantry javelinist

isl - infantry slinger

iar - infantry archer

csw - cavalry sword

csp - cavalry spear

cjv - cavalry javelin

car - cavalry archer

fem - female worker

med - healer

trd - trader

sr - siege - rock thrower

sp - siege - spear/bolt thrower

sr - siege - ram

mer - merchantman ship

bir - bireme

tri - trireme

qui - quinquereme

su1 - super unit 1

su2 - super unit 2

su3 - super unit 3

hr1 - hero 1

hr2 - hero 2

hr3 - hero 3

scn - scenario unit

Actors

Last modified 12 months ago Last modified on Dec 8, 2013 12:38:22 PM