Shader Graph a Used, Unused Variable Bug

Unity Engine
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1

For whatever reason, deleting unused variable, Value, causes my subgraph’s output to change. Note that the subgraph’s output alters after running the project after deleting the unused variable.

The following is the Node Settings for the variable Value. Note that it is completely separated from the Shader Graph.

image
image840×524 17 KB

The following are the changes to the graph caught by GitHub Desktop after just deleting the variable:

image
image1598×1748 297 KB

2

In the event that the video is not playing, here is a gif showing the issue as well:
Bug2-ezgif.com-video-to-gif-converter

3

Hi,

that’s unexpected.
What version of Unity / Shader Graph are you using?
What does the material instance look like, before and after?

4

The error was found on Unity Version 2022.3.15f1 and 2022.3.52f1 as well as Shader Graph 14.0.9 and 14.0.11.

The material instance changes completely after removal of variable.

For more, probably irrelevant, info:

Within my Fullscreen pixelation shader, the removal of used variable Value causes the output of the subgraph to change. Value was completely unused, it’s data no where used. The resolution output of the subgraph Pixelate Screen Position pre-removal equates to (X, Y) whereas after it becomes (X, X*Y), strangely. You can see this in the media posted above if you look closely as the grid goes from 3x3 to 3x9. To get the same output as before removing Value, I had to change the material’s resolution property from (X, Y) to (X, Y/X). This could be done either through the Shader Graph or the Material instance.

I fixed this issue on my end by recreating the subgraph from scratch. After doing this, the node functioned as intended.

5

BugPackage.unitypackage (20.0 KB)
Attached are the files that include the bug.
To reproduce:

  1. Open package in URP project
  2. Ensure Quality & Graphic settings are using package’s URP renderer with Fullscreen pass enabled
  • NOTE: Default scene should be rendering at 5x5 pixels with 5th pixel being all black (lol the shader is unfinished)
  1. Open Fullscreen_Pixelation shader.
  2. Delete Value
  3. Save asset (and play scene?)
  4. Note the scene’s resolution changes from 5x5 to 5x25