Computation

The Computation class is a high-level class in the luma.gl API. It brings together all GPU functionality needed to run GPU compute shaders, in a single, easy-to-use interface.

Computation manages the following responsibilities:

• bindings these can reference textures and uniform buffers
• shader module injection
• debugging - Detailed debug logging of draw calls

The Computation class integrates with

• The @luma.gl/shadertools shader module system: see Shader Assembly.

Usage

import {Computation} from `@luma.gl/engine`;

One of the simplest way to provide attribute data is by using a Geometry object.

Create model object by passing shaders, uniforms, geometry and render it by passing updated uniforms.

import {Computation} from `@luma.gl/engine`;
// construct the model.
const model = new Computation(device, {
  source: COMPUTE_SHADER,
  bindings: {
    uSampler: texture
  },
})

Provide attribute data using Buffer

When using Buffer objects, data remains on GPU and same Buffer object can be shared between multiple models.

// construct the model.
const model = new Computation(device, {
  source: COMPUTE_SHADER,
  attributes: {
    attributeName1: bufferObject,
    attributeName2: device.createBuffer(new Float32Array(...))
  },
  uniforms: {uSampler: texture},
})

On each frame, call the model.draw() function after updating any uniforms (typically matrices).

model.setUniforms({
  uPMatrix: currentProjectionMatrix,
  uMVMatrix: current ComputationViewMatrix
});
model.draw();

Debug shader source (even when shader successful)

// construct the model.
const model = new Computation(device, {
  source: COMPUTE_SHADER,
  debugShaders: true
});

Types

ComputationProps

Property	Type	Description
source	Shader | string	A vertex shader object, or source as a string.
modules		shader modules to be applied (shadertools).
pipelineFactory?		PipelineFactory to use for program creation and caching.
debugShaders?	'error' | 'never' | 'warnings' | 'always'	Specify in what triggers the display shader compilation log (default: 'error').

ComputationProps also include ComputePipelineProps, which are passed through to the ComputePipeline constructor, e.g:

Property	Type	Description
layout	ShaderLayout	Describes how shader attributes and bindings are laid out.
bindings?	Record<string, any>

Fields

pipeline: ComputePipeline

The model's ComputePipeline instance

Methods

constructor(device: Device, props: ComputationProps)

The constructor for the Computation class. Use this to create a new Computation.

destroy(): void

Free GPU resources associated with this model immediately, instead of waiting for garbage collection.

dispatch(pass: ComputePass, x, y, z)

Renders the model with provided uniforms, attributes and samplers

computation.dispatch(computePass, 1);