Operating system: Windows-10-10.0.19041-SP0 64 Bits
Graphics card: GeForce GTX 1080 Ti/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 451.67
Broken: version: 2.83.2, branch: master (modified), commit date: 2020-07-09 05:50, hash: rB239fbf7d936f
Worked: (newest version of Blender that worked as expected)
Short description of error
When displaying Render Result in Image Editor, the panning and zooming performance is extremely bad (about 5-10FPS), and worsens the more user zooms out, so that paradoxically the less pixels of the texture are drawn in the Image Editor space, the worse the performance is. When the identical rendered image is saved and then loaded back as an image texture, and displayed in the very same Image Editor, the performance is perfect (120+FPS).
Here is video of the issue:
Exact steps for others to reproduce the error
- Render at least 2048 * 2048 image
- Open Image Editor and set displayed image to "Render Result"
- Zoom out a bit and pan around, notice the terrible performance
- Save the image from the Image Editor as a file
- Load the saved image as an Image Texture
- Display the loaded image in the same Image Editor
Result: There is huge performance difference in drawing of the identical data in Image Editor, depending on if it's displayed as Image Texture or Render Result
Expected: There is no performance difference between drawing Render Results and Image Textures