Real time rendering

• Improve vertex cache locality
• Convert from right-handed to left-handed space
• Limit weights affecting a single vertex
• Triangulate polygons
• Join identical vertices, optimize indexing

Vertex data

• Compute "hard" per-face normal vectors
• Compute "smooth" per-vertex normal vectors
• Compute tangents and bitangents

Scenegraph

• Collapse the scene graph, transform everything to world coordinates
• Optimize meshes & nodes for fewer drawcalls

Other

• Validate the output structure to ensure maximum stability
• Remove unrequired materials, join duplicates
• Try to correct face winding
• Split large meshes into submeshes (to overcome GPU limitations)