Unity URP render graph passes: declare dependencies before drawing

Start with the resource contract

A custom screen effect is more than a shader invocation. It reads specific data, produces a result and depends on when that data becomes available. Write that contract before moving rendering code between Unity versions. This article follows the Unity 6.0 URP documentation; it is a migration approach, not a claim that one API signature fits every URP release.

Record and execute separately

RecordRenderGraph registers passes and their dependencies. The rendering function supplied through SetRenderFunc records drawing commands when the pass executes. Keep the data needed for that execution in the pass data structure. [1] Avoid letting an effect’s correctness depend on unrelated mutable fields that happen to hold values from a previous camera.

Declare actual texture access

For a raster pass, UseTexture declares a sampled input and SetRenderAttachment declares a render target. The documented path forbids using both on the same texture in one raster pass; use separate textures and passes when needed. [2] Treat resource names as an audit aid: a reviewer should be able to trace every input to a producer and every output to its consumer.

Example: a security-camera tint

Imagine a security camera that displays a green warning tint while an alarm is active. Its first custom pass reads the chosen camera colour and writes a separate tinted texture. A subsequent pass consumes that texture to produce the intended camera output. Describe which camera types qualify, whether the effect runs before or after other post-processing, and what happens when the alarm is inactive. For migration, begin with a simple constant tint, verify the dependency chain, and only then restore the animated alarm pattern. Compare a scene with one camera against a scene with both a game camera and a preview camera. The example defines a design and inspection sequence, not production-ready code.

Migration limits and checks

Compatibility Mode disables render graph, and Unity’s referenced documentation says development effort is directed to the graph path. [3] Record your Editor and URP package versions, then follow their matching examples. Check texture dimensions, format, sample count and camera eligibility before copying old allocation code. Inspect the graph to confirm that outputs are consumed and that expected passes survive culling. Test resizing, disabled effects and the target graphics API. A successful compilation does not establish visual correctness or a performance improvement; compare captures and timings with the original effect.

Sources

1. Write a render pass using the render graph system — Unity Technologies.
2. Use a texture in a render pass — Unity Technologies.
3. Compatibility Mode in URP — Unity Technologies.