Filter the world with one surface.
A backdrop material samples what has already rendered behind it, then applies a TSL filter during the material’s lighting stage. The result is a lens, portal, or glass area without a hand-managed scene pass.
Preparing the shared viewport texture and transparent filter surface…
- backend
- —
- effect
- —
- surface
- —
- source
- —
- render order
- —
- frame ms
- —
The filter graph will be compiled after the renderer selects its backend.
backdropNode
backdropAlphaNode
viewportSafeUV()
viewportLinearDepth
renderOrder 10
The surface is rendered after the opaque world; its backdrop node sees the framebuffer state that exists at that point in the render order.
WebGPU uses the official material-level backdrop path. The forced WebGL2 route is a labeled direct-tint reference because it does not execute the backdrop node.
Derived from the official Backdrop, Backdrop Area, and Refraction examples plus the NodeMaterial, ViewportSharedTextureNode, and TSL docs. Use ?forceWebGL=1 to inspect the explicit fallback.
The renderer could not create the study.