buffergeometry with more than 40k vertices - three.js

Question

I was loading more than 40k vertices in a BufferGeometry.
It worked, but the geometry was not rendered entirely. After decomposing the geometry into separate chunks of 40k vertices, it worked. I was using version r86.
Is this something related to the hardware I am using or to three js?
Please find bellow an adaptation of the code I used to create the BufferGeometry (normalgeom is a Geometry passed as parameter)
var positions = new Float32Array(chunkLength * 3);
var indices = new Uint16Array(chunkLength);
var chunkLength = normalgeom.vertices.length;
for (var i = 0; i < chunkLength; i++)
{
var posInNormalGeom = i;
positions[i * 3] = normalgeom.vertices[posInNormalGeom].x;
positions[i * 3 + 1] = normalgeom.vertices[posInNormalGeom].y;
positions[i * 3 + 2] = normalgeom.vertices[posInNormalGeom].z;
indices[i] = i;
}
var buffGeom = new THREE.BufferGeometry();
buffGeom.addAttribute('position', new THREE.BufferAttribute(positions, 3));
buffGeom.setIndex(new THREE.BufferAttribute(new Uint16Array(indices), 1));
Afterwards, I was creating LineSegments from the buffer
var lineSegs = new THREE.LineSegments(buffGeom, material);
scene.add(lineSegs);
Update: after comment from #TheJim01, the code for splitting the geometry is the following
function makebuffered(normalgeom)
{
var retArrays = new Array();
var chunkLength = normalgeom.vertices.length;
console.log("nr vertices:" + chunkLength);
var remainingVertices = chunkLength;
var processedVertices = 0;
if(chunkLength > 40000)
{
chunkLength = 40000;
}
while(remainingVertices > 0)
{
if(remainingVertices <= chunkLength)
{
chunkLength = remainingVertices;
}
var positions = new Float32Array(chunkLength * 3);
var indices = new Uint32Array(chunkLength);
for (var i = 0; i < chunkLength; i++)
{
var posInNormalGeom = processedVertices + i;
positions[i * 3] = normalgeom.vertices[posInNormalGeom].x;
positions[i * 3 + 1] = normalgeom.vertices[posInNormalGeom].y;
positions[i * 3 + 2] = normalgeom.vertices[posInNormalGeom].z;
indices[i] = i;
}
var buffGeom = new THREE.BufferGeometry();
buffGeom.addAttribute('position', new THREE.BufferAttribute(positions, 3));
buffGeom.setIndex(new THREE.BufferAttribute(new Uint32Array(indices), 1));
retArrays.push(buffGeom);
remainingVertices -= chunkLength;
processedVertices += chunkLength;
}
return retArrays;
}

Answer 1

You have 847666 vertices, which leads to 847666 indices, which is well beyond the bounds of a Uint16Array (max = 65535).
To alleviate this, use Uint32Array instead. All modern browsers (of any consequence) support 32-bit arrays for WebGL buffers.