Changes between Initial Version and Version 1 of NormalMaps

Timestamp:

Dec 26, 2019, 1:40:35 PM (4 years ago)

Author:

Stan

Comment:

Initial version.

NormalMaps

@@ +1 @@
+[[TOC]]
+
+= Normal maps =
+== Introduction ==
+
+Since r12300 0ad supports the usage of special textures called normal maps. From [https://en.wikipedia.org/wiki/Normal_mapping Wikipedia]:
+
+
+> In 3D computer graphics, normal mapping, or Dot3 bump mapping, is a technique used for faking the lighting of bumps and dents – an implementation of bump mapping. It is used to add details without using more polygons.
+
+
+**Note**: Pyrogenesis uses DirectX normal maps even though it is an OpenGL engine. This means if you bake a normal map from for example [https://www.blender.org/ Blender] you will need to invert the Y coordinates of the normal map.
+
+[[Image(DirectXvsOpenGL.png,200)]] 
+
+
+== Usage ==
+
+To enable normal maps, you need to use specific materials in your actor file. You can find the list of the current materials in the SVN version [https://trac.wildfiregames.com/browser/ps/trunk/binaries/data/mods/public/art/materials here]. Materials having normal map support usually have by convention, either `norm` or `parallax`. [wiki:ParallaxNormalMaps Parallax normal maps] are a special kind of normal map.
+
+Here is an example of an actor with a normal map. Notice it's using the `player_trans_parallax.xml` material. 
+
+{{{#!xml
+<?xml version="1.0" encoding="utf-8"?>
+<actor version="1">
+  <castshadow/>
+  <group>
+    <variant frequency="100" name="Object Name">
+      <mesh>structural/object.dae</mesh>
+      <textures>
+        <texture file="structural/object_diffuse.png" name="baseTex"/>
+        <texture file="structural/object_normal.png" name="normTex"/>
+      </textures>
+    </variant>
+  </group>
+  <material>player_trans_parallax.xml</material>
+</actor>
+}}}
+
+If you forget the line 
+
+{{{#!xml
+<texture file="structural/object_normal.png" name="normTex"/>
+}}}
+
+The engine will print an error:
+
+{{{
+ERROR: Actor object: required texture sampler normTex not found (material art/materials/player_trans_parallax.xml)
+}}}
+
+== Additional links ==
+
+Normal map tutorial on the Taleworlds [https://forums.taleworlds.com/index.php?topic=216257.0 forum] especially the James O'Hare [http://i.imgur.com/lpC4V6B.jpg tutorial] part.
+