[[TOC]]
= Parallax Normal Maps =
== Introduction ==
The Pyrogenesis engine supports a type of map called a 'parallax map' in addition to [wiki:NormalMaps normal maps]. Those maps are a special kind of [wiki:NormalMaps normal maps] with an alpha channel. The alpha channel defines the intensity of the parallax effect. 



== Examples == 

**Important**: The parallax map only work if there is actual normal information:

||= Combinations          =||= Result        =||
|| Alpha + Normal          ||[[Image(parallax.png, 200px)]]   ||
|| Normal                  ||[[Image(normal.png, 200px)]]   ||
|| Alpha Only              ||[[Image(alpha-only.png, 200px)]]   ||
|| Plain Normal `#8080ff` ||[[Image(nothing.png, 200px)]]   ||

Full transparency (Alpha at `#000000` (Black)) means maximum depth. 
No transparency (Alpha at `#FFFFFF` (White)) means no parallax.

To disable parallax completely you need to use a [wiki:MaterialSystem material] without:

{{{#!xml
<define name="USE_PARALLAX" value="1"/>
}}}

== Tips ==

* Baking the ambient occlusion (AO) of a more detailed mesh works nicely as an alpha channel mask.
* Just like for the normal avoid noisy alpha channels, and prefer clean simple ones instead.
* In GIMP, you can create your mask as normal channel on top of your existing texture, then paste it as a mask for another layer.
* If your texture uses parallax for everypixel, it's better to set the default alpha color to a medium gray (e.g. `#777777`) this way you have more control over depth. Anything below that value will be a crease, and anything above that value will be a bump.
* If you notice some weird glitches try the edge split modifier in Blender. 

== Caveats ==

* Don't mirror UV coordinates when using parallax as it may generate a color discrepancy.
* Don't use parallax if you don't need to. Sometime a simple normal is all you need.