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  • Published 3 Jun 2020

What is happening with Cycles noise in 2.90?

This is a comparison of what it looks like in 2.83 and 2.90 when the viewport refreshes and accumulates samples from scratch. Note that it lasts for a very short time but it does exist. The noise in 2.90 becomes more blurry and circular. What change did the developers make that caused this? This is not really that big of a deal but I am just curious.

2.83 vs 2.90 Cycles.jpg

EaryChow
3 Jun 2020

10 Comments

3di

looks like it's automatically reducing resolution during movement/initial refresh for faster viewport response. Could be wrong though, maybe ask over at developer feedback.

1
EaryChow Author

* @3d illusions * The phenomenon is gone in the latest daily build, in which the optix viewport denoiser is available to GPUs with Maxwell. I don't know why though.

1
juangea

Try with fatory defaults, you may have a miss configuration in your startup blend

EaryChow Author

* @Juan Gea Rodriguez * No, this is not the case. I tried fatory defaults already and it's still like that.

juangea

* @EaryChow * What settings do you have in the Render Tab, in the performance section, under Viewport?

EaryChow Author

* @Juan Gea Rodriguez * I don't think that matters, I just watched a live stream of someone else using 2.90 today, and I found the same phenomenon. You probably have it too, you just didn't notice. Regardless, here are my settings:

Threads: 

     Mode: Auto-detect
     Threads: 8 (Grey Out)

Tiles: 

     X: 64 px
     Y: 64 px
     Order: Hilbert Spiral
     Progressive Refine (Unchecked)

Acceleration Structure: 

     Use Spatial Splits (Unchecked)
     Use Hair BVH (Checked)
     BVH Time Steps: 0

Final Render: 

      Save Buffers (Unchecked)
      Persistent Image (Unchecked)

Viewport: 

      Pixel SIze: Automatic
      Start Pixels 64 px

These are all my performance settings for both 2.83 and 2.90. I don't think it matters though.

EaryChow Author

* @Juan Gea Rodriguez * It's harder to notice with just the default point light. Just uncheck Scene World and Scene Lights in the viewport shading under render mode. It is easier to see under more complex lightings like an HDRI. Just slowly rotate the view and let the viewport keep refreshing non-stop. It only happens for a very short time but it is there.

Also use the latest daily build as well.

juangea

* @EaryChow * I noticed it, but it's just like in the ver very first sample, you can overcome the unconfortable visual "jump" increasing the start pixels, from 64 to 512 for example, but yes, it seems there has been a change :)

1
EaryChow Author

* @Juan Gea Rodriguez * The phenomenon is gone in the latest daily build, in which the optix viewport denoiser is available to GPUs with Maxwell. I don't know why though.

1
juangea

* @EaryChow * maybe it was just a small bug derived from some change, and it has been fixed already :)

1