Maniphest T93534

Cycles: Persistent Data stops "Animated Seed" from working
Confirmed, LowBUG
Actions

Assigned To
None
Authored By
Alaska (Alaska)
Dec 1 2021, 6:27 AM
Tags
  • BF Blender
  • Render & Cycles
Subscribers
Alaska (Alaska)
Anton Raves (Memento)
Brecht Van Lommel (brecht)
Jesse Yurkovich (deadpin)

Description

System Information
Operating system: Linux-5.15.0-2-amd64-x86_64-with-glibc2.32 64 Bits
Graphics card: NVIDIA GeForce RTX 3090/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 495.44

Blender Version
Broken version: 3.1.0 Alpha, branch: master, commit date: 2021-12-01 00:47, hash: rB1cb99f5808c3
Broken version: 2.93.6
Worked: Unsure

Short description of error
When the Persistent Data option is enabled the Animated Seed option doesn't appear to operate work.

Exact steps for others to reproduce the error

  1. Create a scene in Cycles with noticeable noise.
  2. In the Advanced tab of the Sampling settings, enable Animated Seed (click on the clock icon beside the Seed value)
  3. In the Performance tab of the Render Properties enable Persistent Data
  4. Render an animation.
  5. Notice that the seed pattern doesn't change between frames. Disabling Persistent Data resolves this.

Here is a file that does steps 1-3 for you:

T93534 - Persistent Data - Animated Seed.blend816 KBDownload

Note: The first time I rendered this, frame 1 has a different seed than all the other frames. Subsequent re-renders sees the seed used on frame 1 matching all other frames.

Event Timeline

Alaska (Alaska) created this task.Dec 1 2021, 6:27 AM
Anton Raves (Memento) added a subscriber: Anton Raves (Memento).Dec 1 2021, 9:31 AM
Jesse Yurkovich (deadpin) added a subscriber: Jesse Yurkovich (deadpin).Dec 2 2021, 9:32 AM

I actually can't reproduce this one with a simple scene and when testing CPU or CUDA. Maybe there's more to the repro?

Alaska (Alaska) added a comment.EditedDec 2 2021, 10:44 AM
In T93534#1263329, @Jesse Yurkovich (deadpin) wrote:

I actually can't reproduce this one with a simple scene and when testing CPU or CUDA. Maybe there's more to the repro?

I can still reproduce it with the latest master on CPU, CUDA, and OptiX. Here is a sample file:

T93534 - Persistent Data - Animated Seed.blend816 KBDownload

Note: The first time I rendered this, frame 1 has a different seed than all the other frames. Subsequent re-renders sees the seed used on frame 1 matching all other frames.

Alaska (Alaska) updated the task description.Dec 2 2021, 10:45 AM
Jesse Yurkovich (deadpin) changed the task status from Needs Triage to Confirmed.EditedDec 2 2021, 10:59 AM
Jesse Yurkovich (deadpin) added a project: Render & Cycles.

Ah, I can confirm with your file. The scene I had setup used an animation on the cube so I could see the noise shift or not -- it worked as expected where the animated seed showed differing noise on each frame and non-animated had a steady pattern.

Sure enough, giving your cube even the slightest of animations makes things work.

Brecht Van Lommel (brecht) changed the subtype of this task from "Report" to "Bug".Dec 8 2021, 9:49 PM
Brecht Van Lommel (brecht) triaged this task as Low priority.Dec 9 2021, 6:21 PM
Brecht Van Lommel (brecht) added a subscriber: Brecht Van Lommel (brecht).

This only happens when nothing at all is animated in the scene, so it's pretty artificial. But still would be good to fix.