Corona 3rc3 and rc4 - A lot of Noise Bump Map

[MiltonNazareno]

Hi , I noticed a lot of noise when I use a gray map on the bump. The same map on the displace does not generate as much noise. I also noticed a lot of noise in the interactive mode in simple scenes with good light input.

Thanks

[romullus]

Are you using the same texture for bump and displacement, or are they different?

[MiltonNazareno]

Yes, the same.

[PROH]

Hi. Downloaded your map, and did a quick test. I don't have the same problem. Only major difference between using bump or displacement is the amount of "Primitives".

[pokoy]

I think the 'problem' is that the result from the bump map is sharper and reflects hot light spots. The displaced result is coarser and doesn't have pixel accuracy, thus fails to reflect in the exact same way. If the bump result is too accurate/sharp for you, you can just blur the map a bit, either in Max or in PS.

[Andre_3D]

Hi. Downloaded your map, and did a quick test. I don't have the same problem. Only major difference between using bump or displacement is the amount of "Primitives".

Since to Corona changed some aspects of the shader in the new versions, I have seen this problem... Whenever you use a map with gray tone, not even the denoiser cleans up with all the noise, just the denoiser "Nvidia", but it is not much recommended for animations.
In this exterior scene will always work, there is no indirect light, no walls, no shadows to form noise ... noise has given in the shadows of inner environments, and only completely disappears if you change the maps from Bump to Displacement. Just so the denoiser works.

[romullus]

The bump texture is very lowres, it's basically a noise map (see attached crop). Since denoising algorithm is trying to preserve bump now, what you see might be just very fine bump, derived from poor texture.

While i don't think that this is a bug, i tend to agree that sometimes denoiser is trying too much to preserve bump details and this leads to unbalanced noise. Maybe option to turn off bump preservation, could be added somewhere in render settings?

[Andre_3D]

The bump texture is very lowres, it's basically a noise map (see attached crop). Since denoising algorithm is trying to preserve bump now, what you see might be just very fine bump, derived from poor texture.

While i don't think that this is a bug, i tend to agree that sometimes denoiser is trying too much to preserve bump details and this leads to unbalanced noise. Maybe option to turn off bump preservation, could be added somewhere in render settings?

What I realized is that the problem is not the map, I guess it's the Corona's BUMP. Maps from Arroway, it has high resolution, it always worked in older versions and other renderers. Other maps with gray patterns or 'black and white' or colored, maps with 8000px, with blur 0.01 up to 2.0, whatever map is, if it is on Bump chanel gives problem... This has all been tested, change map, change of scene and etc ... Denoiser only works if you put the maps in Displacement.
I just did a test in another scene now, with Bump the noise doesn't disappear, I can let the denoise activate at 1%, and noises never disappears.
By switching the map channel to Displace, this works.

[maru]

Since Corona v2, denoising tries to preserve bump. Here is an example: https://corona-renderer.com/comparer/uBPZf0
It's always something for something - on one hand you will get nice crisp bump without blurring it excessively, on the other, if the base image is noisy, some of that noise will be preserved too.

If you believe this new behavior is problematic (i.e. that there is more harm than benefit), please let us know, and show examples - we may try improving this, or introduce some switch to revert to the old behavior.

To make things even more interesting - we have autobump in V3, which means that any material with displacement will automatically have a bump map applied.

[gpz]

Do you override 1 when loading the bitmap?

[Andre_3D]

Since Corona v2, denoising tries to preserve bump. Here is an example: https://corona-renderer.com/comparer/uBPZf0
It's always something for something - on one hand you will get nice crisp bump without blurring it excessively, on the other, if the base image is noisy, some of that noise will be preserved too.

If you believe this new behavior is problematic (i.e. that there is more harm than benefit), please let us know, and show examples - we may try improving this, or introduce some switch to revert to the old behavior.

To make things even more interesting - we have autobump in V3, which means that any material with displacement will automatically have a bump map applied.

---------------

override 1 for normal map, yes ... bump no

'Milton' sent the example from the floor, I sent the example of the wooden furniture... here the Bump is generally keeping a lot of noise in the scene. When used or displace has less noise.
I'm going to download the RC7 version now to see if anything has improved.

I guess it used to be better, because even though it 'blurred' more, the noise disappeared and then it was possible to increment with render pass the bump/sharpen etc... now as the noise does not disappear neither with 1.0 of denoiser nor leaving at 2%, stayed complicated to maintain a good quality standard in the image, depending on the scene in which it is working, also occurs noise flick when doing animation, and before that did not happen.