SimplifyModifier: Move to BufferGeometry.

[Mugen87]

Related issue: -

Description

SimplifyModifier no longer relies on Geometry. The modifier now has a dependency to BufferGeometryUtils.

[mrdoob]

Thanks!

[Mugen87]

I had a look at SubdivisionModifier today and it's tricky to honor texture coordinates when using BufferGeometry.

The problem is the algorithm assumes vertices are merged. And this is possible with Geometry even if texture coordinates a different for two or more identical vertices. However, this does not work when performing the merge with BufferGeometry since all vertex data (normals, colors, uvs) have to match.

Since you can only use BufferGeometryUtils.merge() for an efficient vertex merge when dropping all other vertex information, a conversion to BufferGeometry only works if we remove features from the modifier.

[mrdoob]

Thanks for taking a look 🙏

Since SubdivisionModifier never got to work properly for Geometry either, what do you think about just removing it?

[Mugen87]

Even better! 😊

[mrdoob]

Lets do that then! 🙌

[Mugen87]

I'll make a PR 👍 .