IRay render aliasing textures? Only between certain colors ...

Ptrope

I'm trying to convert the materials of my Dart over to IRay, and found this weird artifact in the render. The texture map is 5000x3565 and wraps completely around the main hull of the ship. In rendering, it shows really bad aliasing along the border of the black pinstripe and the red, but NOT between the pinstripe and the white. Any ideas? This image shows the render, and the same section of the map at full size - that line is clean. I used one of the DAZ Uber car paint materials and added the texture map to the diffuse node.

murgatroyd314

I can't tell from your picture how much of the problem is in the actual render, and how much is coming from JPEG compression (which is quite visible throughout). Are you rendering directly to JPEG, or to some less lossy format?

Ptrope

I'm not sure you're actually looking at the problem - the edge between the black pinstripe and the red surface, in the render, is a mess of aliasing, even though the edge between the pinstripe and the white area is smooth in the same render. It's not a matter of lossy compression - this is clearly visible onscreen before saving the render. Maybe it's an artifact of D|S compressing the texture map before applying it to the model - I don't know how that is handled by the software; I know from plenty of experience that red is a lousy color range to compress, but I've never seen this kind of jagged aliasing caused by compression even from a clean original image - it's usually evident from murky, uneven areas in the flat color, not at edges where colors chamge.

kitakoredaz

have you tried to change  render setting >Advanced tab> Texture compression, Threshold values? 

if you need not any pre-compression, set both Medium and High threshold value, more than your texture image size. 

then your texture may not get any compression when ds  render.

 

mark_z2487

I realize this is an old thread, but if someone searches for this,

I was having an issue with texture maps and edges showing extreme aliasing in a scene that I purchased, it set the render settings

I set them back to default and the problem went away so I compared all the settings, the culprit was “Pixel Filter Radius”

In the bad file it was set to 0, the default is 1.50