"Cubemap Size" affects procedural texture's scale in the reflections #61739

New Issue

Marcin Twarowski · 2019-02-20T09:47:20+01:00

Marcin Twarowski commented

2019-02-20 09:47:20 +01:00

Win 10, GTX 1080
Blender 2.80 2019-02-19 23:18 855b3e68ef

When you bake a cubemap at lower resolutions like 128px, procedural textures have incorrect scale in reflections:

See attached blend file:texture_bake_scale_bug.blend

Win 10, GTX 1080 Blender 2.80 2019-02-19 23:18 855b3e68ef27 When you bake a cubemap at lower resolutions like 128px, procedural textures have incorrect scale in reflections: ![cubemap_texture_size_bug_02.png](https://archive.blender.org/developer/F6668290/cubemap_texture_size_bug_02.png) ![cubemap_texture_size_bug_01.png](https://archive.blender.org/developer/F6668293/cubemap_texture_size_bug_01.png) ![cubemap_texture_size_bug_03.png](https://archive.blender.org/developer/F6668296/cubemap_texture_size_bug_03.png) See attached blend file:[texture_bake_scale_bug.blend](https://archive.blender.org/developer/F6668286/texture_bake_scale_bug.blend)

Marcin Twarowski commented

2019-02-20 09:47:20 +01:00

Added subscriber: @MarcinTwarowski

msalv commented

2019-02-20 13:24:23 +01:00

Added subscriber: @moisessalvador

msalv commented

2019-02-20 13:24:23 +01:00

What you see is a combination of a moire effect, due to small scale of the texture and the low cubemap resolution. Another way of putting it, the texture is so small than when it's captured on the cubemap filtered at a lower res, it just happens to look like a large scale version of the same texture, an optical illusion. But if you use any other procedural texture, or the texture at a larger size, you see that lowres cubemaps don't change their scale. Like in this image with the lowest cubemap resolution possible.

texture_bake_scale_bug.blend

What you see is a combination of a moire effect, due to small scale of the texture and the low cubemap resolution. Another way of putting it, the texture is so small than when it's captured on the cubemap filtered at a lower res, it just happens to look like a large scale version of the same texture, an optical illusion. But if you use any other procedural texture, or the texture at a larger size, you see that lowres cubemaps don't change their scale. Like in this image with the lowest cubemap resolution possible. ![image.png](https://archive.blender.org/developer/F6670236/image.png) [texture_bake_scale_bug.blend](https://archive.blender.org/developer/F6670249/texture_bake_scale_bug.blend)

Marcin Twarowski commented

2019-02-20 13:42:05 +01:00

Moire effect doesn't explain this:

It's a simple noise texture with a scale of 100. texture_bake_scale_bug_noise.blend

If it's indeed a moire effect then i guess it needs better filtering.

Moire effect doesn't explain this: ![noise_texture_cubemap.PNG](https://archive.blender.org/developer/F6670356/noise_texture_cubemap.PNG) It's a simple noise texture with a scale of 100. [texture_bake_scale_bug_noise.blend](https://archive.blender.org/developer/F6670386/texture_bake_scale_bug_noise.blend) If it's indeed a moire effect then i guess it needs better filtering.

msalv commented

2019-02-20 14:01:33 +01:00

The noise is smaller than the size of a pixel in the cubemap, and thus the small noise disappears in the downscale process while the few ones that appear look big because that's how big the pixels are. It's like downsampling a picture of stars in photoshop, that's what happens, and no filtering algorithm would solve that 100%. It's definitely NOT procedural textures changing scale, because then it would change scale even with big textures like in the imaged I used above

Marcin Twarowski commented

2019-02-20 14:46:37 +01:00

Ok then, If there's nothing to be done about it.

Marcin Twarowski commented

2019-02-21 11:21:49 +01:00

Changed status from 'Open' to: 'Archived'

Marcin Twarowski closed this issue

2019-02-21 11:21:49 +01:00

Marcin Twarowski self-assigned this 2019-02-21 11:21:49 +01:00

Sign in to join this conversation.

No Label

Download

What's New

Blender Studio

Manual

Developers Blog

Documentation

Benchmark

Blender Conference

Development Fund

One-time Donations

"Cubemap Size" affects procedural texture's scale in the reflections #61739