Documentation

⚠

3D objects may not appear inside the blur

WithoutPostProcessing captures at BeforeRenderingTransparents. Any 3D object that hasn't rendered yet at that point is entirely absent from the captured texture.

Workaround: use WithPostProcessing on a Screen Space Overlay canvas — it captures after all geometry has finished rendering.

⚠

World Space canvas panels are always occluded by Screen Space Camera canvases

Unity draws Screen Space Camera canvases on top of World Space canvases regardless of scene hierarchy. Additionally, the two canvas modes capture at different stages, so neither blur can see the other's panel content.

There is no workaround for this combination. Change the Screen Space Camera canvas to Screen Space Overlay instead — Overlay always renders after World Space geometry, so layering and blur capture both work correctly.

⚠

Blur panels rendered by the same camera cannot see each other's blur output

When two BlurImage panels are rendered by the same camera, both capture at BeforeRenderingTransparents — the same moment in the same frame. The front panel's blur runs before the back panel has been composited into the color buffer, so it samples the raw scene rather than the already-blurred backdrop.

Screen Space Overlay: no workaround. All Overlay canvases render through the same implicit camera and share the same capture point.

Workaround — separate canvases on separate cameras via Camera Stack: place each panel on its own Screen Space Camera canvas, each assigned to a different camera. Stack the cameras so the popup camera renders after the backdrop camera. The popup's BlurImage then captures a color buffer that already contains the backdrop blur.

1. Keep your Main Camera with Culling Mask set to Everything.
2. Add a second camera. Set Render Type to Overlay and Culling Mask to UI only. Match projection, FOV, and clipping planes to the Main Camera.
3. Make the new camera a child of the Main Camera and zero its local position and rotation.
4. In the Main Camera's Camera Stack, add the new camera as the last entry.
5. Set the backdrop canvas to Screen Space Camera, Render Camera = Main Camera.
6. Set the popup canvas to Screen Space Camera, Render Camera = Stack Camera.

Both canvases must use Screen Space Camera mode — placing both panels on the same canvas or the same camera will not work even with a Camera Stack. Use a separate BlurProfile per panel to control each independently.

Screen Space Overlay blurs everything

Overlay + WithPostProcessing captures after all geometry — opaque, transparent, world-space, and 3D objects — and includes post-processing effects. It is the most reliable option when you need the blur to include all scene content.

UI panel is black / shows no blur

• Confirm the Blur Renderer Feature is added and enabled on the active URP Renderer asset.

• Ensure a BlurProfile is assigned to the BlurImage component.

• If using WithPostProcessing, confirm the Canvas is set to Screen Space Overlay.

Blur appears pixelated or blocky

• Reduce downsample — high values produce a low-resolution RT that becomes visible at low blur strength or when intensity is below 1.

• Increase iterations or blurOffset to widen the blur and soften the pixelation.

Blur stops updating / freezes unexpectedly

• Check updateMode on the profile — Throttled with throttleFps = 0 intentionally freezes the blur after the first frame.

• Confirm at least one BlurImage referencing the profile is enabled and visible — profiles with no active consumers stop running automatically.

Normal map shows dark fringe / black edges at high bump strength

• The distortion UV is sampling outside the blur RT's scissor region. The scissor automatically expands by bumpStrength to cover the distortion range — confirm bumpStrength is not larger than the panel's screen-space margin allows.

• Move the panel away from screen edges, or reduce bumpStrength.

Performance is poor

• Switch to Dual Kawase (lowest cost per quality).

• Increase downsample to 4 and reduce iterations to 2.

• See Performance Tips below for profiling-level optimisations.

Setup Wizard shows no renderers

• Open it manually via Tools → URPUIBlur → Setup Wizard.

• If no renderers appear, create a URP Universal Renderer asset first: Assets → Create → Rendering → URP Universal Renderer.

BlurImage looks correct in Scene view but wrong in Game view

• The Scene view camera is separate from the Game camera and may capture at a different resolution or with different post-processing. Always treat Game view as the reference.

• If the Scene view blur looks distorted, this is expected — the scissor rect is computed from the Game camera's viewport, not the Scene camera's.

Share one profile across multiple BlurImages

If multiple panels need identical blur parameters, assign them the same BlurProfile. The pass chain runs once and all panels sample the same result — zero additional GPU cost per extra panel.

Use Update Mode to reduce how often the blur re-runs

Set updateMode to Throttled for panels over a mostly-still background. Skipped frames reuse the last blurred result at zero added cost.

Set throttleFps to 0 to freeze the blur after its first frame — ideal for pause menus, modals, and any background that does not move while the panel is open.

Assign the same CaptureMode to all BlurImages on a profile

Each distinct CaptureMode branch (WithoutPostProcessing / WithPostProcessing) is a separate pass chain with its own RTHandles. Mixing capture modes on the same profile doubles the GPU and memory cost for that profile.

Keep the active profile count low

Each active profile is an independent pass chain. Consolidate panels that share parameters into fewer profiles rather than giving every panel its own profile.

Disable BlurImage components when not visible

A profile's pass chain stops running automatically when all its BlurImage consumers are disabled or invisible. Disable the component (not just the GameObject's alpha) when a panel is fully hidden to eliminate its cost entirely.