Pixelated textures in render

Xen2k

I encounter an issue with pixelated textures in my renders.
The product uses 4k textures (https://www.daz3d.com/ajc-ultimate-arena-fight) and in the texture itself there are not such pixelations.

After checking my render settings I'm still clueless. Does anyone know how this issue can be solved?

[Edit: This product does not use any glossy/bump/normal maps. Could this maybe lead to this problem? Closeups of other textures like Genesis 8 characters don't cause any issues.]

fred9803

Yes that's usually a sign of a small texture map in close-up. It that one a 4K map or one of the smaller ones?

Xen2k

It's a 4k map. I would have thought that this is a sufficient resolution.

Edit: Increasing the texture to 8k reduced the pixelation. 12k even more so (although this seems to be a rather unusual/large size for a simple texture).

Catherine3678ab

.jpeg? .png or .tiff are better texture images. It would need to be remade to look nice though if it's a .jpeg.

Xen2k

Catherine3678ab said:

.jpeg? .png or .tiff are better texture images. It would need to be remade to look nice though if it's a .jpeg.

The original is a JPG. Remaking it would be out of my current toolset. I guess upsizing the resolution remains my best bet then.

fred9803

I wouldn't think that increasing the image dimensions would make any difference, unless you use an AI image upscaler.

Xen2k

fred9803 said:

I wouldn't think that increasing the image dimensions would make any difference, unless you use an AI image upscaler.

Interpolation in GIMP worked quite okay.

Ascania

Xen2k said:

and in the texture itself there are not such pixelations.

They are there, even if you can't easily see them. Those are JPEG compression artifacts.

 

Xen2k

Ascania said:

Xen2k said:

and in the texture itself there are not such pixelations.

They are there, even if you can't easily see them. Those are JPEG compression artifacts.

 

And now I understand why experts recommend PNG for this kind of application. 

UHF

Do you have Iray compression enabled?  (Its Iray, Advanced Tab, Texture Compression.) I've dialed mine to 5500 which cleaned up severe artifacts in 4k images.

Cenobite

UHF said:

Do you have Iray compression enabled?  (Its Iray, Advanced Tab, Texture Compression.) I've dialed mine to 5500 which cleaned up severe artifacts in 4k images.

Does this solve those texture issues that are not 4k+ i doubt changing scale will solve the issue, the image has to be created for that resolution just changing something to 4k ,8k or 16k will only increase the file size and doesn't impact image quality all that much, If you take a small render then resize it with paintshop by changing dimensions to make it larger all you will do is decrease resolution as the image pixelates & blurrs the larger you make the picture.

T-Rex below uses an 8K texture thats why it looks so detailed even in default render settings no increase to render quality options needed he renders good at any resolution.

UHF

Cenobite said:

Does this solve those texture issues that are not 4k+ i doubt changing scale will solve the issue, the image has to be created for that resolution just changing something to 4k ,8k or 16k will only increase the file size and doesn't impact image quality all that much, If you take a small render then resize it with paintshop by changing dimensions to make it larger all you will do is decrease resolution as the image pixelates & blurrs the larger you make the picture.

T-Rex below uses an 8K texture thats why it looks so detailed even in default render settings no increase to render quality options needed he renders good at any resolution.

Cenobite, I think you should read the original post, and I also think you should consider the example image that the original poster showed.

Clearly, in a busier and complex scene you really won't see any compression artifacts, there's just too much happening as you showed in your example.

However, if you see simple textures close up, compression artifacts can become quite critical and annoyingly visible.  These issues also compound themselves when other texture layers are invovled which are often extracted from the original texture.  (If you've ever worked with older materials, then you'd know there some real limits to how much you can extract from a single diffuse map.  ...artifacts gallore.)

I've attached two images to show what I'm talking about.  Its a close up of a character standing next to a wall. The 'wall' is a 4k texture spread across the whole scene, and no artifacts are visible a short distance away.  However, up close you can clearly see jpg like compression.  I did locate that region of the diffuse map, and its hardly perfect, but any artifacts are made worse by Daz's default compression algorithm.

To properly clean this up and save memory without harming the render, the Scene Optimizer Script should be used.  As it is, the uncompressed render uses 11.9GB of my GPU.

 

Default Compression (512, 1024)

No Compression (5555, 5555)

 

Cenobite

UHF said:

Cenobite said:

Does this solve those texture issues that are not 4k+ i doubt changing scale will solve the issue, the image has to be created for that resolution just changing something to 4k ,8k or 16k will only increase the file size and doesn't impact image quality all that much, If you take a small render then resize it with paintshop by changing dimensions to make it larger all you will do is decrease resolution as the image pixelates & blurrs the larger you make the picture.

T-Rex below uses an 8K texture thats why it looks so detailed even in default render settings no increase to render quality options needed he renders good at any resolution.

Cenobite, I think you should read the original post, and I also think you should consider the example image that the original poster showed.

Clearly, in a busier and complex scene you really won't see any compression artifacts, there's just too much happening as you showed in your example.

However, if you see simple textures close up, compression artifacts can become quite critical and annoyingly visible.  These issues also compound themselves when other texture layers are invovled which are often extracted from the original texture.  (If you've ever worked with older materials, then you'd know there some real limits to how much you can extract from a single diffuse map.  ...artifacts gallore.)

I've attached two images to show what I'm talking about.  Its a close up of a character standing next to a wall. The 'wall' is a 4k texture spread across the whole scene, and no artifacts are visible a short distance away.  However, up close you can clearly see jpg like compression.  I did locate that region of the diffuse map, and its hardly perfect, but any artifacts are made worse by Daz's default compression algorithm.

To properly clean this up and save memory without harming the render, the Scene Optimizer Script should be used.  As it is, the uncompressed render uses 11.9GB of my GPU.

 

Default Compression (512, 1024)

No Compression (5555, 5555)

I see your point the crap in the top right corner and along the very right edge you cleaned up with compression  a bit in the second frame, it think it's scaling the resolution isn't quite set at defaults very good, it's just factoring the whole scene not the different scales the shot is being taken at, it's like the edge of the frame has been streched out of focus because of the perspective, is that more of a lighting factor and how that light reflects off the displacement bump map & the textures reflectiveness, might cause distortion in the image, could try reducing reflectivity maybe in surface parameters for that particular prop. Still comes down to how close you get to a texture if it reveals high detail the closer you get or just pixels out like the corner of this shot. Could try smoothing out some shadows cast by your light source to reduce that square pixel look at certain angles.

From the look of it the light source in the scene isn't giving you the best render outcomes the chararcter skin looks fuzzy & lacks definition a proper light source would provide, in both renders the cheek on the left side is blurry i think thats a shadows problem from the light source used, you can soften the shadows to make the light source render clearer less pixelated with more focus that highlights any detail.

UHF

Cenobite, I'm not actually looking for help.  I'm try to explain to you that if you can see plain textures up close you stand a decent chance that you might see compression artifacts caused by Daz\Iray.  You won't see it in a busy scene which was your example.

The example render I provided was exactly that, and it wasn't meant to be some sort of actual effort on my behalf.  In fact it was my first test render using Iray, and fortunately I had read in another thread that the stock Daz\Iray compression could cause issues.  If I didn't know that Daz did that by default, I would have gone crazy hunting for the source.  [I've been using Octane for years, and I've never seen these kinds rendering artifacts before.]

The lesson for vendors is to ensure that surfaces likely to been seen up close, should use the maximum amount of texture space possible.  In this case, the texture is 4k, but its covering like 4 posts, and there is a lot of blank space on that texture map.  The down side is that cleaning it up is way more work for vendors.

The lesson for would be artists such as the original poster, is to beware Daz's built in compression.

Cenobite

It's the same deal as this, The hair in this render pixels out because of some hair setting not smoothing out each pixel, it's probably the same deal with your render some setting to compress the pixels making the image less distored with square looking pixels.

Everything else is perfect in this pic but the hair piece used, the finer hair particles are leaving square pixels which should render out but i get this mario brothers 2d pixel experience when i complete the render.. Seems to be the type of shader used because this doesn't effect other hair pieces.

Xen2k

UHF said:

Do you have Iray compression enabled?  (Its Iray, Advanced Tab, Texture Compression.) I've dialed mine to 5500 which cleaned up severe artifacts in 4k images.

Sorry for the late reply and thanks for this advise!

I tested a "high threshold" of 5500 and it did seem to improve the quality.
Now I'm not sure if (or how much) this increases the GPU usage. The 8 GB VRAM of my GPU are quite often a critical resource.

chris-2599934

Cenobite said:

It's the same deal as this, The hair in this render pixels out because of some hair setting not smoothing out each pixel, it's probably the same deal with your render some setting to compress the pixels making the image less distored with square looking pixels.

Everything else is perfect in this pic but the hair piece used, the finer hair particles are leaving square pixels which should render out but i get this mario brothers 2d pixel experience when i complete the render.. Seems to be the type of shader used because this doesn't effect other hair pieces.

This is a bug introduced in a recent version of iray - it interacts badly with some hair shaders, and annoyingly it affects some of the best hairstyling PAs: Outoftouch, Windfield, etc. Fortunately, there's an easy workaround: Select the hair and for all its surfaces set Cutout Opacity to 0.99 insted of 1. That seems to fix it right away.

Xen2k

chris-2599934 said:

Cenobite said:

It's the same deal as this, The hair in this render pixels out because of some hair setting not smoothing out each pixel, it's probably the same deal with your render some setting to compress the pixels making the image less distored with square looking pixels.

Everything else is perfect in this pic but the hair piece used, the finer hair particles are leaving square pixels which should render out but i get this mario brothers 2d pixel experience when i complete the render.. Seems to be the type of shader used because this doesn't effect other hair pieces.

This is a bug introduced in a recent version of iray - it interacts badly with some hair shaders, and annoyingly it affects some of the best hairstyling PAs: Outoftouch, Windfield, etc. Fortunately, there's an easy workaround: Select the hair and for all its surfaces set Cutout Opacity to 0.99 insted of 1. That seems to fix it right away.

Dialing down the SSS value to 0 in the surface settings is an alternative approach for those sparks in the hair.
Hair shaders that don't use SSS settings don't seem to be affected by this Iray engine bug.