The Challenge
Placing debris on terrain is a common task in game development, but achieving a natural look can be challenging, especially on steep slopes or areas with significant height differences. Traditional methods often force objects to conform to the terrain surface, which flattens them and compromises their natural shape and appearance.
The Innovation
Vertex color-based approach: Pre-compute the center of each mesh part and store it in vertex colors. Shader samples terrain height at the center, not per-vertex.
Pre-Computation Tool
Editor tool analyzes mesh loose parts (like individual rocks in a pile), calculates their centers, and bakes the data into vertex colors.
Shader Implementation
Shader reads vertex color to get part center position, samples terrain height at that point, then moves all vertices of that part up/down together.
Shape Preservation
Unlike traditional methods, each rock maintains its original shape. Only the group's position adjusts to match terrain elevation.
Final Result
Natural-looking debris placement that perfectly matches terrain height while preserving the artistic intent of the original models.