The SPINE_TRIANGLECHECK directive in the Spine-Unity runtime is not primarily intended for performance optimization. Instead, it serves a crucial role in ensuring the correctness of the rendering process. The comment "Not for optimization. Do not disable." indicates that this check is essential for maintaining the integrity of the mesh data and preventing potential rendering issues.
When SPINE_TRIANGLECHECK is enabled, it avoids unnecessary calls to mesh.SetTriangles by comparing render instructions between frames. While this does introduce some overhead due to mesh comparisons, it is generally outweighed by the cost of repeatedly setting triangles, which can be more expensive in terms of performance. The comparison ensures that SetTriangles is only called when there is an actual change, thus balancing the performance cost.
The reason you might not see similar operations in other Spine runtimes (like UE or Three.js) is due to differences in how these platforms handle mesh data and rendering. Each runtime is optimized according to the specific needs and capabilities of the platform it targets. Unity, for instance, has particular performance characteristics and constraints that necessitate such checks to ensure efficient rendering.
For more detailed information on performance optimization in Spine-Unity, you can refer to the following resources:
These resources provide comprehensive guidelines on optimizing your Spine animations and understanding the trade-offs involved in different optimization techniques.
