GPUComputePassEncoder: setBindGroup() method
============================================

**Experimental:** **This is an experimental technology**  
Check the Browser compatibility table carefully before using this in production.

 The **`setBindGroup()`** method of the
 `GPUComputePassEncoder` interface sets the `GPUBindGroup` to use for subsequent compute commands, for a given index.

Syntax
------


```js
setBindGroup(index, bindGroup)
setBindGroup(index, bindGroup, dynamicOffsets)
setBindGroup(index, bindGroup, dynamicOffsets, dynamicOffsetsStart,
             dynamicOffsetsLength)
```

### Parameters

`index`

The index to set the bind group at. This matches the `n` index value of the corresponding `@group(n)` attribute in the shader code (`GPUShaderModule`) used in the related pipeline.

`bindGroup`

The `GPUBindGroup` to use for subsequent compute commands.

`dynamicOffsets` Optional

A value specifying the offset, in bytes, for each entry in `bindGroup` with `hasDynamicOffset: true` set (i.e. in the descriptor of the `GPUDevice.createBindGroupLayout()` call that created the `GPUBindGroupLayout` object that the `bindGroup` is based on). This value can be:

* An array of numbers specifying the different offsets.
* A `Uint32Array` containing numbers specifying the offsets.

If a `Uint32Array` value is specified for `dynamicOffsets`, both of the following parameters are also required:

`dynamicOffsetsStart`

A number specifying the offset, in array elements, into `dynamicOffsetsData`, where the dynamic offset data begins.

`dynamicOffsetsLength`

A number specifying the number of dynamic offset values to be read from in `dynamicOffsetsData`.

### Return value

None (`Undefined`).

### Exceptions

For `setBindGroup()` calls that use a `Uint32Array` value for `dynamicOffsets`, the call will throw with a `RangeError` `DOMException` if:

* `dynamicOffsetsStart` is less than 0.
* `dynamicOffsetsStart` + `dynamicOffsetsLength` is greater than `dynamicOffsets.length`.
### Validation

The following criteria must be met when calling **`dispatchWorkgroups()`**, otherwise a `GPUValidationError` is generated and the `GPUComputePassEncoder` becomes invalid:

* `index` is less than or equal to the `GPUDevice`'s `maxBindGroups` limit.
* `dynamicOffsets.length` is the same as the number of entries in `bindGroup` with `hasDynamicOffset: true` set.
* For `bindGroup` entries where the bound `buffer`'s `type` is `"uniform"` (see `GPUDevice.createBindGroupLayout()`), each number in `dynamicOffsets` is a multiple of the `GPUDevice`'s `minUniformBufferOffsetAlignment` limit.
* For `bindGroup` entries where the bound `buffer`'s `type` is `"storage"` or `"read-only-storage"` (see `GPUDevice.createBindGroupLayout()`), each number in `dynamicOffsets` is a multiple of the `GPUDevice`'s `minStorageBufferOffsetAlignment` limit.
* For each `bindGroup` entry, the bound `buffer`'s `offset`, plus the corresponding layout entry's `minBindingSize`, plus the corresponding dynamic offset specified in `dynamicOffsets`, is less than or equal to the bound `buffer`'s `size`.
Examples
--------

In our basic compute demo, several commands are recorded via a `GPUCommandEncoder`. Most of these commands originate from the `GPUComputePassEncoder` created via `beginComputePass()`. The `setBindGroup()` call used here is the simplest form, just specifying index and bind group.


```js
const BUFFER\_SIZE = 1000;

// ...

// Create GPUCommandEncoder to encode commands to issue to the GPU
const commandEncoder = device.createCommandEncoder();

// Initiate render pass
const passEncoder = commandEncoder.beginComputePass();

// Issue commands
passEncoder.setPipeline(computePipeline);
passEncoder.setBindGroup(0, bindGroup);
passEncoder.dispatchWorkgroups(Math.ceil(BUFFER\_SIZE / 64));

// End the render pass
passEncoder.end();

// Copy output buffer to staging buffer
commandEncoder.copyBufferToBuffer(
  output,
  0, // Source offset
  stagingBuffer,
  0, // Destination offset
  BUFFER\_SIZE,
);

// End frame by passing array of command buffers to command queue for execution
device.queue.submit([commandEncoder.finish()]);

// ...
```

Specifications
--------------

| Specification |
| --- |
| WebGPU # programmable-passes-bind-groups |

Browser compatibility
---------------------

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See also
--------

* The WebGPU API