I was ready to jump into more practical examples and to give more direction to my project after the last post, but came across some articles that improve upon the principles presented in the previous ones. Here, they only list 4 principles that encompass the most important things to take into account when creating a 3D model for an interactive environment:
Model after the reference – Already covered in previous articles, basing your models on real life objects or other works.
Knowing the limits – Taking into account both the technological limits on the hardware (affordable polygon count, available rendering techniques, etc) and the “interaction limits”, or what purpose is that object going to have in the game, and how would the model fit that best.
Simplification – Paying special attention to use every polygon with a purpose, without wasting GPU power.
Topological Perfection – Ensure that the model passes through the following checklist:
- No N-GON: No polygons with more than 4 sides, as it slows the rendering process dramatically.
- No Holes: Merge all corresponding vertices so holes wont show up will smoothing the geometry.
- No Non-planar surface: All vertices on a quad should always be in the same plane.
- No Non-Manifold creation:
- Not having 3 or more faces sharing the same edge.
- Not having faces sharing a vertex without also sharing an edge.
- Not having faces sharing an edge while also having opposite normals.
- No Stack-and-Intersect meshing: Not having objects composed of diferent meshes with faces that are not supposed to be seen, as it generates pointless Z-fighting wasting GPU resources.