Controlling flipping when tiling textures



  • @franklcr said in Controlling flipping when tiling textures:

    Is it possible for the object file to contain its own settings for tile flipping that could override Poser's settings?

    Yes, OBJ files are "uv mapped" to determine how a texture is applied to the model. It looks like that might be the case for the OBJ you are trying to use. Is that rope available somewhere so I can look at the UVs and the OBJ?


  • Poser Ambassadors

    I agree with @Deecey on the possibility of mirrored UV mapping.



  • @Deecey Looks like it is part of something called "Ropes Kit" by R. Kawecki from back around 2005. I've had it around a long time, obviously. It has a lot of knots, loops, lengths of rope, etc. and looks like they all follow this behavior with the tiling. I don't imagine it's practical to try to go through all of the OBJ files and edit them to fix that. Guess I need to look for some newer rope props!



  • @franklcr
    It looks like those ropes are textured. Are you not using the textures that come with it?



  • @Deecey No. The textures that came with it are all woven rope. I wanted to use a twisted rope texture as I show in that render I posted earlier.



  • @franklcr
    OK what you will need to do is take a look at the textures he used for his ropes. I'd be curious to see if he is also using a seamless texture. I have a feeling he isn't.



  • @Deecey I already know that he's using a tiling texture. If you simply replace his texture with another tiling texture, you see the same effect I showed in my render above - the tiles get flipped, even though he doesn't have the Mirror U or V boxes checked.

    Now, looking at what's available as far as 3D rope models, looks like there's not anything out there anywhere near as varied as what Kawecki has done. I've never gotten into an OBJ file to try to edit it so no idea how much effort it would be, or if there's an editor around that would enable me to fix this problem.


  • Poser Ambassadors

    My bet is UV's as well. Pedantic note on terminology - any texture can be tiled or repeated, but each new tile or repetition will have an obvious seam at the edges. Seamless textures are those where the texture has been edited when created so that the pixels at the edges match the opposite edges - when it is tiled there is no seam visible (no flipping required, it's already been done).

    When I've built objects like this (tree trunks etc) to use seamless tiling textures, I chop the mesh up into rough squares (called shells or islands) in my UV editor then stack all the pieces on top of each other & force them to a square i.e. filling the 0-1 UV space 100%. It looks like when these props were made the creator had each alternate UV shell stacked but mirrored for some reason.

    Should be fixable in a UV editor - Blender is free & has UV tools, or UVMapper is basic but also free.



  • @caisson
    Yes it was the UVs. He sent me the OBJ and half of them were flipped. Quick fix.



  • I contacted Ricardo Kawecki who created the rope props I was trying to use to ask him about this. He confirmed that he created the model with the tiling hardwired to flip as I'm seeing. But his solution was to not use textures that don't work when every other tile is flipped. Here's his response to me:

    Hi
    It is the way that the ropes are UV mapped. The mapping use repeating a texture, but the repetition is not copying the same texture. Instead it are back to back. (one segment is straight and the next one is inverted, the next is straight and so on...)
    This mapping scheme allows you much more flexibility on the texture used and produce very little seams.
    Of course it can cause some problems. If you use an inclined texture you will get a zig-zag pattern, I suppose that is your case.
    Solution: Use a texture with straight lines (horizontal or vertical) or with little inclination or use the textures included with the ropes.

    Ricardo

    So maybe the best thing is to not use any prop made my this guy.

    On the other hand, Deecey fixed the UVs in one of the props and it textures correctly now! All I need to do is try to understand what she did so I can fix any other of these rope props I might want to use.