Makeup Rendering Begins!

Makeup has been one of the customization options that I've wanted to support, but  because of some minor implementation details I kept bumping it back to focus on other tasks. No more! I dedicated a few hours to working with Daz and set up an automated rendering pipeline for makeup, which means the next update will include the ability to define some basic makeup for characters. Right now the makeup options will be eye shadow, blush, and lipstick. The makeup works with the same dynamic clothing system I have set up already, so the intensity and colour of the makeup can be varied.

The delay in getting this makeup rendering system in place stems from the fact that makeup and clothing items are treated as fundamentally different by Daz Studio (the 3D rendering program used for Lab Rats 2). Clothing items, like bras, shirts, and pants, are 3D meshes warped to fit the characters body. To render clothing items the characters body is not rendered but is set to still occlude (ie. hide things behind) clothing. The result is clothing items that look correct when layered with separate naked character images. Makeup, on the other hand, is treated as a 2D texture applied onto the 3D character's skin. This makes the previous method impossible to use.

The first step to solve this was to find a way to render the makeup and ONLY the makeup, without including the rest of the model. To do this the model is set to be transparent everywhere other than the area covered by the 2D texture of the makeup. The colour of the models skin is then turned pure white so that the area covered by the makeup ends up being a greyscale image with pure white showing where it is illuminated and shadows shown as darker greys where appropriate. This works perfectly for face on images but breaks down for other angles; with a transparent character model we end up rendering the back side of our makeup when there should be a face in the way!

The next step is to properly occlude the makeup so only the faces of the makeup that should be visible are rendered. Some rendering engines include the option to "cull" or ignore textures seen from the wrong side of a surface, but that option is not available in Daz. To get around this a geometry shell is created. This shell is essentially a duplicate of the model offset by a small amount. By setting the offset amount to a tiny negative number a shell that sits just under the skin of our original model is created. In the same way as clothing images use the model to occlude the clothing item the makeup render can then use the geometry shell of the model to occlude the model itself. The final result is makeup that is rendered properly from all angles and is no more difficult to create new versions of than clothing items are now. 

The first batch of renders is being created now, I will try and have an example posted up soon! Until then I will be working on writing more content for the sexual positions in v0.11.