Parallax Normal Maps

Introduction

The Pyrogenesis engine supports a type of map called a 'parallax map' in addition to normal maps. Those maps are a special kind of 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
Normal
Alpha Only
Plain Normal #8080ff

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 material without:

<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.