Search Issue Tracker

Fixed in 22.1.X

Votes

0

Found in [Package]

12.0.0

Issue ID

1347301

Regression

No

[URP] Premultiply blend mode in Shader Graph not rendering correctly

Package: Scriptable Render Pipeline Universal

-

Reproduction steps:
1. Open project in Premultiply.zip and open SampleScene
2. Enter Play Mode and inspect the 2 cubes side by sideaa

Expected result: the cubes are the same
Actual result: the cubes are different (one of them is hard to see because of transparency)

Reproducible with: 11.0.0 (2021.1.15f1), 12.0.0 (2021.2.0b4, 2022.1.0a3)
Could not test with:
7.7.0 (2019.4.29f1) because the customer written shader was pink (errors in the shader)
4.10.0 (2018.4.36f1) both shaders are pink

Note: One of the shaders is Ulnit/Premultiply, the other is Premultiply shader created using Shader Graph

  1. Resolution Note (fix version 22.1):

    If a Material or a Shadergraph blend mode was set to Premultiply previously. It did Alpha blend in practice, which is incorrect (the bug).

    Now the Premultiply does the correct thing. So to keep the previous look, the upgrade changes the blend mode to Alpha (+ PreserveSpec) mode (only affects upgrades).
    The user needs to set the Blend mode back to Premultiply to get the new result.

    For material: Blend mode -> Premultiply blend
    For shadergraph: Open graph -> Blend mode (from target config) to Premultiply -> Save

    Fixed in 2022.1.0b1

Add comment

Log in to post comment

All about bugs

View bugs we have successfully reproduced, and vote for the bugs you want to see fixed most urgently.