How do you decide where to use pure geometry or Normalmaps?

ZombieDawgs

Hey guys

This is something that's been bugging me for a long time, when you're creating environments and so on, where do you call the line and say "This doesn't need to be baked high to low" and just model it straight up? 

BradleyWascher

This has to do a lot with technical restrains or style but here is the main idea to take away. Think about objects as having large, medium, small, and micro details/forms. Now if you have a metal sheet with a hundred bolts that are small the geometry cost would out weight the shader cost in terms of performance. An that relationship is really what you have to ask yourself. Depending on your style most of the time you can get away with modeling the large and medium forms and having the small and micro details in the normal.

defragger

It depends. Will there be Anti-Alias, the timeframe, poly-counts, ... maybe there will be limited texture space (for mobile). Everything has to be taken into account.

Its generally good to know different approaches and technics. I use custom vertex normals a lot, whenever I dont have the time or dont feel the need for a full highpoly bake. Check it out if you havent seen it:

http://polycount.com/discussion/154664/a-short-explanation-about-custom-vertex-normals-tutorial

http://wiki.polycount.com/wiki/VertexNormal#Smoother_Shading

You can use something like this for mobile:

http://www.gdcvault.com/play/1022324/The-Ultimate-Trim-Texturing-Techniques

I think the idea of a somewhat "modular" normalmap for the edges is amazing and I can see that in production. If I had to do multi story buildings for example, I would probably use that for the upper stories (on the outside), or a modular approach. Depends on what you want to do or what technical requirements you are facing.

sr3d

Use Normal Map for fine details like follicles, wrinkles, cavities, veins, hair strands, etc.

If your humanoid polygon budget is 3000 polygons, then all your muscle definition detail will be in your normal map (like Skyrim).

If your humanoid polygon budget for your humanoid is 27000, then you can add somewhat detailed muscle groups in the mesh.