Reduce memory garbage in fromBufferGeometry and mergeVertices.

[ngokevin]

Description of the problem

Geometry.fromBufferGeometry and mergeVertices has some temp arrays and objects:

Examples are like tempNormals, tempUVs, tempUVs2. And in mergeVertices, unique, changes, faceIndicesToRemove

Also if Geometry.fromBufferGeometry is getting called from one of the three.js Geometries (e.g., BoxGeometry), can have a flag that tells fromBufferGeometry to not need to clone like the bounding box, just share the reference since the buffer geometry is discarded.

Examples are like boundingBox.clone() and boundingSphere.clone().

Perhaps I'll end up moving to use BufferGeometry completely later (we do bunch of accessing of the faces array), but should be easy to improve memory a bit in these two methods.

Three.js version

• Dev
• r94

Browser

• All of them
• Chrome
• Firefox
• Internet Explorer

OS

• All of them
• Windows
• macOS
• Linux
• Android
• iOS

Hardware Requirements (graphics card, VR Device, ...)

[mrdoob]

Perhaps I'll end up moving to use BufferGeometry completely later

Is this for Supercraft?

[ngokevin]

Yeah.