RGB Curvature baking is broken if model is small

[Yousung]

Hello developers, I used 'RGB Curvature' after the update before, and the baking process was broken once.
At that time it was solved with Edit-Reset settings.

This time, when baking the RGB Curvature, the texture was broken.
(On the first try, it baked normally.)
I tried Reset settings again this time, but it didn't fix it.

The strange thing is that the other example samples from 3DC are baked normally.

I thought the scene was broken, so I exported the high-poly and low-poly data and then imported it again in a new scene, but the problem was not solved.

Share files by uploading them to Dropbox.
Does anyone have the same problem as me?



 

 

▼ Dropbox file ▼
https://www.dropbox.com/sh/12vlitxs23lcesl/AAAfULUYoeRPsmGGgjhvd24Xa?dl=0

Edited October 19, 2021 by Yousung

[Yousung]

 

In V4 it works fine.

Since RGB Curvature has been added recently, I don't know if this is a bug or not, but it seems that the cause has been found.

It seems that LowPoly lacks polygons.
It was confirmed that the quality of the RGB Curvature increases as the polygon is divided.

But since I mainly use it as a game asset, I can't keep dividing the faces like this.

Can you please improve this problem?

[digman]

Out of town today but will look at the problem when I get back this evening unless Carlosan looks at the problem as well and figures it out. 

[Carlosan]

Confirmed and reported.

Thanks for point it up.

Note: Why is the low model smaller than the high model ?

[Carlosan]

Scaling up -a little- low model, RGB bake is ok,

 

sharing scaled project files:

https://www.dropbox.com/s/tmwltywebsrp05i/211019_RGB Curvature baking issue.zip?dl=0

[Yousung]

Thanks for checking out @Carlosan.
But this confuses me even more.
It's late at night, so I can't see the details.

After checking the file

First, lowpoly modeling needs to maintain its size.
The protrusion on the top was intended to be processed with baking.
So it will look smaller than highpoly.

If the size is increased as much as the protruding part, distortion will occur at the upper part of the cylinder as shown in the image.
I don't want results like this.
So the size of the lowpoly mesh should be kept as much as possible.

Second, in general, if you work on a retopology after making a high-poly mesh, it will have a size similar to that of high-poly.
After that, through the baking process, maps (normal, AO, Curvature, position, etc...) are extracted.

3DC also goes through this process to extract a normal map.
However, it is very strange to increase the size of the lowpoly to extract the Curvature.

If the Normal map was extracted normally, other maps should do the same.

Edited October 19, 2021 by Yousung

[Carlosan]

Where did you do the high poly and the backing ?

[Yousung]

All work was done on 3DC only.

[Yousung]

To check for baking problems
I took the high and low mesh created by 3DC to the SP and tried baking.
In SP, it bakes just fine.

Edit1 ) add SP baking image

Edited October 19, 2021 by Yousung

[Carlosan]

Bug reported. Thanks

* Using default mesh scale everything looks ok, we dont need to resize any mesh.

[Carlosan]

Sidenote: avoid to work at this tiny scale

Your current model size

 

[Yousung]

Yep, I'll have to test about the scale again tomorrow. 

[digman]

I would switch back to the old style curvature for now if you need to get this done atm.

The new RGB cavity curvature baking works in most cases but still needs some fine turning I believe.  

You could send the file to Andrew to help improve the RBG cavity baking. 

I found a few places where the uvs were getting stretched a bit but it was not so bad to cause the problem. 

I made no changes in the scene scale nor scaled the object using the older default curvature baking.

[Yousung]

To summarize the test and the information I found out.
When baking RGB Curvatures...

- It is affected by the size of the object.
- Affected by the density of polygons.

 

It is affected by the size of the object.

As Carlosan said, the object needs to be large enough to start baking properly.

If I increase the size of the Highpoly and Lowpoly meshes by x10 with the Transform tool on my attached model, it starts to bake normally.

However, it is still partially noisy.

 

Affected by the density of polygons.

This is currently the biggest influence on RGB Curvature baking.

Before baking, copy the lowpoly that has completed the UV work, put the subdivide on it, and bake it separately to see the RGB Curvature that comes out neatly.

 

As a little trick, you can export/import this RGB Curvature as a colormap and import it to use it in the Lowpoly mesh.

However, this method is a temporary expedient, and an image with partially distorted edges often comes out.
(Baking with Triangulate does not solve the problem.)

A more definitive troubleshooting is needed.

@Andrew Shpagin

[Yousung]

4 hours ago, digman said:

I would switch back to the old style curvature for now if you need to get this done atm.

 

Thanks digman.
Fortunately, the mesh I made is for studying the PBR baking workflow, so it's not an urgent issue.