Cycles--UV Layers--Problems

Hi, all.

I’ve seen a few UV issues on here, but nothing really matches up with my problem.

I’m creating a banner as part of a logo. I need to map the entire banner to a tileable cloth texture for displacement. I need to map the center of the banner for some text that I created in Photoshop.

  1. How does one work with UV layers in Cycles? I’ve done this in BI before, but Cycles is killing me.

  2. I save out the text in PNG and TIF formats without an issue, but when I import the image into Blender, it’s a big, black, blocky mess. Interestingly, when I select the alpha value, the text is right there. Has anyone seen this before?

  1. You know you can add a texture coordinate node to define the mapping and select the UV socket. This does not change anything as this is the default setting. Instead of the texture coordinate node use an attribute node and supply it with the name of your UV map.
  2. PNG files should work fine now with Cycles, with TIF I’m not sure, I would tend to avoid them.

Here’s a screenshot of problem #2. That black, blocky mess is text from Photoshop–“Forging Elite Fitness”. It’s a PNG, there’s no discernible issue with the picture file.

This is Blender 2.63 svn 36006. This was happening in a Blender 2.62 build as well. Anyone have a clue what causes this?

I wanted to bump this thread back to the top. I’m using a 2.65 build from Graphicall on a Mac OSX x64 system, and this same problem with PNGs for UV textures is happening. JPEG works fine, but I get a white stroke around my black text that I don’t want. Unsure if there is a way to premultiply the texture (would that even get rid of the white stroke?) but a PNG should be the way around this, except for the aforementioned issue.

Anyone seen this before?

I’m using the 6.64 build available from the main blender site and I’m having this issue with .png files and .tif files. They show up as blocks. I’m also having issue with UV Layering as well but I’m using Octane so not sure if anyone can help with it here >.>

I understand the concept behind UV layers (attribute nodes to texture nodes to shader nodes to mix shader nodes–I think), but this PNG thing is killing me. You and I can’t be the only ones having this problem.

Bug reported to BF, if it is the same thing, not 100% sure, we’ll see.

Thanks, Ray!

I saw the update from Brecht on the bug report. I figured out what he was saying and implemented a quick test case. You see the node setup and the ridiculous black bar that is the “Hello World” PNG text from Photoshop that is UV mapped onto a plane.

Maybe I’m just not nearly as high-speed in 3D as I thought, but this seems like an awful lot of steps for a VERY simple idea–PNGs have an alpha channel built-in so I want to use it; otherwise I would have used a JPEG.

I don’t know. I’m glad there’s a solution, but it seems overly complex, and what is the deal with the PNG image displaying like that?!

Thanks, Infantry, at least we have a workaround. We shouldn’t have to resort to such tricks though, the alpha should be ignored if not being used.

I think the devs suffer from bug fixing fatigue every now and then. A week ago I had a disagreement with Ton in a bug report, but thankfully Brecht jumped in and fixed it. Now Brecht isn’t being reasonable about this one… Someone else needs to talk to them, can’t do it all myself.

Thats the problem with permultiplied alpha. At all places where you have full transparency the color is undefined (devision by zero) and half transparent areas (for example antialiased edges) loose color precession. This is more or less an issue with Inkscape (with premultiplied alpha) as with Blender. Just export an rainbow gradient, combined with an alpha mask, import it in gimp, separate the alpha channel and look at the RGB colors without alpha-channel. You will see how badly the colors of transparent areas are managed. It is always assumed that the image is blended over an opaque area with a fixed color. Blender assumes black and Inkscape white. Some other application might assume something else.