Using the vertex bus and index bus for meshes.

[AlexAPPi]

When writing a terrain system, I need to reuse buffers, it would be nice to implement this for the mesh API.

const maxNumIndex = 123;
const indexArray = new Uint32Array(maxNumIndex);

....
const indexBufferOptions = undefined; // TODO for webgpu support
const indexBuffer  = new pc.IndexBuffer(
    app.graphicsDevice,
    pc.INDEXFORMAT_UINT32,
    indexArray.length,
    pc.BUFFER_STATIC,
    indexArray,
    indexBufferOptions
);

const mesh = new pc.Mesh(app.graphicsDevice);
mesh.indexBuffer[0] = indexBuffer;

....

mesh.setIndices(indexArray, 10); // <- here i use 1 buffer
mesh.update(pc.PRIMITIVE_TRIANGLES, false);

engine/src/scene/mesh.js

Line 1021 in 57cbfd4

indexBuffer.writeData(srcIndices, this._geometryData.indexCount);

engine/src/platform/graphics/index-buffer.js

Line 196 in 57cbfd4

const indices = this._lockTypedArray();

• A similar situation with vertices

[mvaligursky]

Hi @AlexAPPi .. could please provide more details of what you're trying to do? I'm not sure I understand this issue.

[AlexAPPi]

Hi @AlexAPPi .. could please provide more details of what you're trying to do? I'm not sure I understand this issue.

Hi! I use the same buffer for the model, and modify it, every time it is unloaded to the GPU, the engine makes a copy of the same buffer, although there is no point in doing this, because this is the same buffer.

[mvaligursky]

The Mesh has two possible ways to use it, see here: https://api.playcanvas.com/classes/Engine.Mesh.html

• a simple way - see example at that link
• a more manual way of using Vertex and Index buffer directly

What you can do is to create Vertex and Index buffer yourself and upload data to them as needed. In this case, you would not use mesh.setIndices() and mesh.update(), but manage buffers yourself.

I'll close this as I believe this is what you need, but please re-open if I missed something.