Using GPU parameters

GPU parameters control culling, depth and stencil tests, blending, and rasterization. Choose the owner from when the value needs to change:

State	Where to set it	When it can change
Culling, depth tests, blending, multisampling	RenderPipelineProps.parameters	Create a different pipeline; Engine Model.setParameters() manages this for you.
Clear values and read-only attachments	RenderPassProps	Begin a new pass.
Viewport, scissor rectangle, blend constant, stencil reference	renderPass.setParameters()	Between draws in the same pass.

Configure a model

model.setParameters({
  depthWriteEnabled: true,
  depthCompare: 'less-equal',
  cullMode: 'back'
});

const renderPass = device.beginRenderPass({
  clearColor: [0, 0, 0, 1],
  clearDepth: 1
});
model.draw(renderPass);
renderPass.end();
device.submit();

The target must have a depth attachment compatible with the pipeline's depthFormat. Inside AnimationLoop.onRender, the loop handles submission.

Change a viewport between draws

renderPass.setParameters({viewport: [0, 0, 800, 600]});
model.draw(renderPass);
renderPass.setParameters({viewport: [600, 0, 200, 150]});
model.draw(renderPass);

Viewport and scissor coordinates use drawing-buffer pixels, not CSS pixels. Use scissorRect to restrict writes; changing a viewport alone does not clip to its rectangle.

Next steps

• GPU parameter reference lists accepted values.
• Rendering explains targets, passes, and submission.
• Antialiasing explains sampling choices.