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Poor Color Blending Issues


RabenWulf
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The banding ?

looks as video quality or graphic card driver for me...

 

could you share the project ?

and test the same project in another computer ?

 

are you using 4.5 Beta11 ?

 

Yes using the beta, but this issue happened in the non beta versions as well. I'm setting up another PC now as we speak to test it out, if I get the same results ill post a project file thats doing it.

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Ok, so I brought my old 6 core AMD 1100T back to the land of the living. It has an nvidia 560ti in it and about 16 gigs of RAM. Put a new copy of Windows 8 in it, installed all the usual drivers. Got the demo of 3d Coat, plugged in a wacom intuos 3 (with drivers) and basically got it all set up.

 

Problem still exist. I'm starting to believe the banding is part of 3d coat. Two different computers, and seeing it on a youtube video leaves me to think that either its an option I am missing or just something with 3d coat that some might not be noticing.

Try starting with a dark value, like a dark dark blue, and then raise the lightness, blending it outward. Its easy to see the banding that way.

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I have been following the thread, could it be possible that it is a DX 9 Texture Linear Filtering problem... 3DC uses DX9...

Turn off Linear Texture Filtering under the View menu and it is more like we would paint in Photoshop to see if that helps.

The camera is the zoom the closer you are to the model the more of the pixels you will see.

Here is a read on DX 9 Texture filtering. In the article is the advantages and drawbacks of Linear Filtering... 

You could trying re- installing DX 9 though I do not think that is the problem.

https://msdn.microsoft.com/en-us/library/windows/desktop/bb206250%28v=vs.85%29.aspx

 

The above is just adding information to the thread discussion.

Edited by digman
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3DC does indeed have a color banding issue, but I've never seen it be anywhere near as bad as in the pics you posted.

For me, I need to seriously look at a texture up close for it to just barely be noticeable. No idea why its so bad for you, but I just thought I'd post to say that its not a completely isolated case.

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I can clearly see the banding on this section of the sphere in the gradient and even the section I painted over there is a gradient.

I am running 24 bit color in Linux which uses open gl for running 3DC.

I also run a DX 9  windows 3DC version under wine in Linux for beta testing.

The banding appears in both versions.

I checked my monitor / TV to make sure it was functioning properly using a gradient test. No banding was noticed...

 

Nvidia Video card GTX 550 Ti...

post-518-0-16366200-1422983879_thumb.png

Edited by digman
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@ RabenWulf, I would post a Mantis report plus provide a link to this forum thread...

 

Done, though I really have no idea how it ranks on the severity scale. For me personally its extremely high, in part because the only reason I picked up 3d coat was for the texture painting. Every other feature I have covered in Modo/Zbrush. While  Andrew is working on the paintroom though, it might be worth addressing, especially if other users pick it up for the texturing features.

http://3d-coat.com/mantis/view.php?id=1775

 

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Filll tool

Gradient mode

dark blue to white

fill layer

 

attachicon.gifGradient.jpg

 

//edit

Ty Digman

 

adding a screen capture with TextFiltering = off

 

attachicon.gifLinearFiltering-off.jpg

 

Yeah when I do a gradient I get something like this instead. If I chose more extreme values it becomes even more apparent.

 

ScreenHunter_81Feb031329_zps86eb3dd2.jpg

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very visible...

 

when you import 

 

you had tested No cuda version or used another monitor and nothing changed, i suppose...

 

sorry duno how to help, i cant reproduce here

 

* there is a new Beta11 if you like to try

 

 

Yep, tried just about every version thats come out since 4.5beta. Just now with version 11. On two different computers, going to try a third now but at this point I dont think its going to change anything. Also 1 cintiq screen, 1 tv screen and 2 different monitors (samsung, LG and wacom). I know its def not the monitor, especially since its only 3d coat showing it...but I did give it some consideration just in case despite the inconsistency.  Both openGL and DX versions attempted as well. I'm wondering if its an nvidia issue perhaps? Are you using ATI?

 

Add: You know whats weird, I am not sure its strictly related to the paintroom. If I apply a matcap onto a sculpt for example, you see some banding as well... or with the new environment background getting blurred it shows up too.

Edited by RabenWulf
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Hey guys!

Comparing images uploaded to forum is pointless because forum software aggressively compresses uploaded JPEG attachments (it even alters PNG files, hopefully in a lossless way). Same with YouTube videos. In the optimistic case we deal with a single lossy YouTube compression. In a pessimistic one: with screen recorder's lossy compression and additional YouTube compression. There's also the problem with monitors. They vary in displayable gamut and they may be calibrated or not. So, some of us may see banding on the image and some might not. Also, when exporting to 8-bit images, let's not forget about dithering algorithms that might kick in (if implemented).

I know I'm talking obvious things here, but I saw those JPEGS and the above immediately came to my mind.

 

Maybe we could establish a test scene and compare numerical values of pixels in exported 32-bit textures (EXR)?

 

I'm trying to reproduce the banding issue with the blue gradient fill over a 10242 texture, but I don't see it.

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I will check the on a 32 bit exr file. Now 3DC can internally export the correct gradient. I load png files to the forum for this type of stuff so there is lossless compression on them. Pointless to show is a little extreme wording. What I see in my exported image is the same as inside 3DC.

 

What I am curious to know, why do some see it and not others...

Warm or cool monitor settings, I run mine to the cool side for better printing...

DX9 problems but also seen in my OPGL linux both are running 24bit.

Video card setup and drivers?

Some type of Monitors or TVs being used as monitors like me...

Lots to think about here...

The problem for me is not that bad unless I am really zoom in and 3DC is used in production work but something is going on so and maybe Andrew can shed a light on it...

Edited by digman
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The compression via image upload isnt the issue in this particular case in part because its still showing what we are seeing live on the screen inside of 3d coat. If anything its making the issue even more evident.

More importantly, how does anyone export anything over 8bits from 3d coat? I have not found a way and everything that comes out of it is 8bits.

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Through File→Export Objects & Textures, or through TexturesExport. Both have an option to export to OpenEXR.

 

I see, so exr is the only way to get anything above 8 bits out of 3d coat? That seems a bit odd. I did verify that picking exr pumped out something above 8 bits but the same visual banding seen on screen is present in the export as well. Sorry I probably shouldnt go off on that tangent atm, at least until we can figure out the source and or solution of the banding.

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HDR is another option. But some say it's not full 32-bit float.

 

Sorry I probably shouldnt go off on that tangent atm, at least until we can figure out the source and or solution of the banding.

 

I'm sorry, I lost you here. What tangent do you speak of?

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HDR is another option. But some say it's not full 32-bit float.

 

 

I'm sorry, I lost you here. What tangent do you speak of?

 

No problem, I meant asking questions about exporting anything more than 8bit textures, since it doesnt necessarily address the subject of banding. I was expecting or looking for some kind of setting that may address this inside of 3d coat itself (similar to that of PS or Krita). This line if inquiry though would lead us off on a tangent, and ultimately pointless if the banding issue cant be identified and resolved. =)

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Ok, my Gradient is better that yours... so I am not sure what is going on your end to produce that bad gradient and it might be effecting your brushes as well.

I used your test file.

 

See if it happens to you while doing the whole object with a normal brush type (non rectangular).

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Ok, when you say gradient you are talking about the fill bucket tool... The reason I used a rectangle spline was to control the area the gradient was in. A normal brush will just fill the whole object with a gradient. The end result looks just like the image I uploaded except over the whole object.

I might not be understanding what you mean by your use of gradient... Remember in my other postings I am only trying to help. I also posted on your mantis report.

I do see some slight banding in my gradient...

Please explain...

post-518-0-56962400-1423033926_thumb.png

Edited by digman
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Ok, when you say gradient you are talking about the fill bucket tool... The reason I used a rectangle spline was to control the area the gradient was in. A normal brush will just fill the whole object with a gradient. The end result looks just like the image I uploaded except over the whole object.

I might not be understanding what you mean by your use of gradient... Remember in my other postings I am only trying to help. I also posted on your mantis report.

I do see some slight banding in my gradient...

Please explain...

 

Yep, referring to the fill bucket tool with the gradient option. The reason I wanted to see if the same happens for you with a fill object or on a larger scale is because I noticed when I work big or with larger brushes, the effect is more visible, but if I zoom in and work small it is not... this leaves me to believe its some how based on scale as well. The banding seems range from small and large depending on scale and whats being done.. Also No worries I know you are trying to help, hope it doesnt come across as combative at all. I'm focused on trying to ID the issue as well, as its quite literally a frustrating experience. =)

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