Merge Vertices

THREE.BufferGeometry extension to generate and optimize triangle indices by deduping vertex attributes and generating new triangle indices. Also provides a couple bug fixes and utility functions for BufferGeometry.

Demo here!

Submitted in this PR to THREE.js.

Use

<script src=".../three.js"></script>
<script src=".../BufferGeometryOptimizeTriangleIndices.js"></script>

<script>

  // Create buffer geometry with no triangle indices
  var sphere = new THREE.SphereGeometry( 1, 100, 100 );
  var bufgeom = ( new THREE.BufferGeometry() ).fromGeometry( sphere );

  // The buffer geometry is taking '' with all attributes
  console.log( `${ THREE.BufferGeometryUtils.estimateBytesUsed( bufgeom ) * 1000 }kb` );

  // Optimize the buffer geometry and generate triangle indices
  bufgeom.mergeVertices();

  // The buffer geometry is taking '' with all attributes
  console.log( `${ THREE.BufferGeometryUtils.estimateBytesUsed( bufgeom ) * 1000 }kb` );

</script>

API

InterleavedBufferAttribute.copy

InterleavedBufferAttribute.clone

Missing copy and clone functions.

BufferGeometryUtils.estimateBytesUsed(bufferGeometry)

Returns the memory allocated for the geometry (vertex attribute and index arrays) as bytes.

BufferGeometryUtils.interleaveAttributes(attributes)

Converts the provided normal attributes into a set of interleaved attributes that share a buffer.

BufferGeometry.mergeVertices(tolerance = 1e-4)

Updates the vertex attributes and index arrays with optimized, deduped versions representing the same mesh.

The tolerance argument determines the decimal precision used when deduping vertex attributes.