Function createCustomMesh

examples/src/buffer-mesh-instance.ts:62–137

* Create cube geometry with custom BufferGeometry. * @param engine - Engine * @param size - Cube size * @returns Cube mesh

(engine: Engine, size: number)

 * @returns Cube mesh
 */
function createCustomMesh(engine: Engine, size: number): Mesh {
  const geometry = new BufferMesh(engine, "CustomCubeGeometry");

  // Create vertices data.
  // prettier-ignore
  const vertices: Float32Array = new Float32Array([
          // Up
          -size, size, -size, 0, 1, 0, size, size, -size, 0, 1, 0, size, size, size, 0, 1, 0, -size, size, size, 0, 1, 0,
          // Down
          -size, -size, -size, 0, -1, 0, size, -size, -size, 0, -1, 0, size, -size, size, 0, -1, 0, -size, -size, size, 0, -1, 0,
          // Left
          -size, size, -size, -1, 0, 0, -size, size, size, -1, 0, 0, -size, -size, size, -1, 0, 0, -size, -size, -size, -1, 0, 0,
          // Right
          size, size, -size, 1, 0, 0, size, size, size, 1, 0, 0, size, -size, size, 1, 0, 0, size, -size, -size, 1, 0, 0,
          // Front
          -size, size, size, 0, 0, 1, size, size, size, 0, 0, 1, size, -size, size, 0, 0, 1, -size, -size, size, 0, 0, 1,
          // Back
          -size, size, -size, 0, 0, -1, size, size, -size, 0, 0, -1, size, -size, -size, 0, 0, -1, -size, -size, -size, 0, 0, -1]);

  // Create instance data.
  const instanceCount = 4000;
  const instanceStride = 6;
  const instanceData: Float32Array = new Float32Array(instanceCount * instanceStride);
  for (let i = 0; i < instanceCount; i++) {
    const offset = i * instanceStride;
    // instance offset
    instanceData[offset] = (Math.random() - 0.5) * 60;
    instanceData[offset + 1] = (Math.random() - 0.5) * 60;
    instanceData[offset + 2] = (Math.random() - 0.5) * 60;
    // instance color
    instanceData[offset + 3] = Math.random();
    instanceData[offset + 4] = Math.random();
    instanceData[offset + 5] = Math.random();
  }

  // Create indices data.
  // prettier-ignore
  const indices: Uint16Array = new Uint16Array([
          // Up
          0, 2, 1, 2, 0, 3,
          // Down
          4, 6, 7, 6, 4, 5,
          // Left
          8, 10, 9, 10, 8, 11,
          // Right
          12, 14, 15, 14, 12, 13,
          // Front
          16, 18, 17, 18, 16, 19,
          // Back
          20, 22, 23, 22, 20, 21]);

  // Create gpu vertex buffer and index buffer.
  const vertexBuffer = new Buffer(engine, BufferBindFlag.VertexBuffer, vertices, BufferUsage.Static);
  const instanceVertexBuffer = new Buffer(engine, BufferBindFlag.VertexBuffer, instanceData, BufferUsage.Static);
  const indexBuffer = new Buffer(engine, BufferBindFlag.IndexBuffer, indices, BufferUsage.Static);

  // Bind buffer
  geometry.setVertexBufferBinding(vertexBuffer, 24, 0);