Question about minimum achievable simplification rate in mesh simplify

[754978334]

Hi,

I've been experimenting with meshopt_simplifyWithAttributes on a specific model and noticed that there seems to be a lower bound on the achievable simplification rate. For this mesh, the simplifier does not seem to reduce it below ~36% of the original triangle count. Even when I request a higher simplification (e.g., targeting 20%), the output still ends up around 36%.

I understand that this may be due to the algorithm trying to preserve visual quality and avoid excessive geometric error at very low triangle counts. However, for experimental purposes, I would like to push the simplification further, even at the cost of higher visual error.

Is there any way to override or reduce this minimum simplification threshold? Or is this behavior inherent to the simplifier’s internal heuristics?

Thanks in advance for your guidance!

[754978334]

Sorry I found the answer in the README.md — I should have read it more carefully before asking.

Target error is an approximate measure of the deviation from the original mesh using distance normalized to [0..1] range (e.g. 1e-2f means that simplifier will try to maintain the error to be below 1% of the mesh extents). Note that the simplifier attempts to produce the requested number of indices at minimal error, but because of topological restrictions and error limit it is not guaranteed to reach the target index count and can stop earlier.

[zeux]

Two relevant options that might be of interest are https://meshoptimizer.org/#permissive-simplification and component pruning (meshopt_SimplifyPrune flag); both can help reach the target count depending on the mesh structure.