Surface Extractor Mesh Simplification

David Williams · **Joined:** Sun May 04, 2008 6:35 pm **Posts:** 1827

petersvp wrote:

Downsampling the volume data itself is vvery heavy operation. In Crafterria, I generate LODs based on the mesh decimator. Downsampling may require TransVoxel for seamliss meshes, while the decimator approach does not introduce any seams if I modify the function to never merge vertices of region boundaries.

I do agree downsampling can have some problems. And I'm not against decimation, but until we do more LOD work in Cubiquity it is hard to say what is best. And perhaps we can still do a hybrid, decimating the downsampled meshes. I don't know yet but I do hope to play with OpenMesh one day.

kklouzal · **Posted:** Thu Sep 04, 2014 8:22 pm

Another great use for this feature would be in scenarios that use the MarchingCubesExtractor and have very small voxels in a very large volume.

For example, the user could generate a random terrain, then do a second pass over the volume adding in buildings that were actual models converted to voxel data. The advantage of having the small voxels means the building models, once converted to voxel data and placed into the volume, could retain most, if not all, of their original quality.

Such a scenario, even though it is using the smooth extractor, would have many vertices that could be simplified away drastically decreasing the vertex count.

petersvp · **Joined:** Tue Apr 08, 2014 5:10 pm **Posts:** 124

To make region boundaries seamless, you muast patch MeshDecimator the following way:

In include\PolyVoxCore\MeshDecimator.inl
make following function immediately return false:

Code:

bool MeshDecimator<VertexType>::canCollapseRegionEdge(uint32_t uSrc, uint32_t uDst)

this way you get seamless regions

Surface Extractor Mesh Simplification

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