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    Texel dialog

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    • Chris FullmerC Offline
      Chris Fullmer
      last edited by

      http://forums.sketchucation.com/viewtopic.php?f=323&t=22658

      There is the link, see if that does what you would like.

      Lately you've been tan, suspicious for the winter.
      All my Plugins I've written

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      • thomthomT Offline
        thomthom
        last edited by

        I see no image attached...

        Thomas Thomassen โ€” SketchUp Monkey & Coding addict
        List of my plugins and link to the CookieWare fund

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        • A Offline
          alz
          last edited by

          Hi Chris!

          Thanks for the suggestion. Goldilocks is based on the current viewpoint, whereas a texel ratio is more of a way to verify that all textures being used are all at the same pixel ratio.

          Maybe Goldilocks had components that could lead to a texel script/plugin/filter/style.

          ๐Ÿ˜„

          An example in the image -- the left side has mixed texels, the right had uniform texels

          http://www.ericchadwick.com/examples/provost/byf2_figure6.jpg

          EDIT:

          @thomthom said:

          I see no image attached...

          ...weird! The image is blocked within the <img> code. And it shows up in the Preview. Here's the raw url:

          Link Preview Image

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          • A Offline
            alz
            last edited by

            Okay double weird -- that image example doesn't always come through.

            Here's a better example -- POOR texel ratio:

            http://www.renderheads.com/portfolio/UVAutoRatio/docs/images/df9zb6gq_50qm5tw4tx.png

            PERFECT texel ratio:

            http://www.renderheads.com/portfolio/UVAutoRatio/docs/images/df9zb6gq_51c3tn8cg6.png

            hmmm... perhaps I'm just confusing myself. This texel concept is not the UV scale, independent of the texture/material size (thinks)

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            • thomthomT Offline
              thomthom
              last edited by

              I looked up texel on wikipedia: http://en.wikipedia.org/wiki/Texel_%28graphics%29
              Didn't make me much wiser - seemed rather vague...

              As for your request: is it info on how many times a texture repeats across a surface?

              Thomas Thomassen โ€” SketchUp Monkey & Coding addict
              List of my plugins and link to the CookieWare fund

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              • Chris FullmerC Offline
                Chris Fullmer
                last edited by

                This is my understanding of what he is looking for:

                I think it is more like pixels per mm (or meter or whatever your brain thinks in, for me its inches ๐Ÿ˜ฎ ). And that is not mm in screen space, but mm in model space.

                So your textures should all be about uniform pixels per cm. Maybe you decide 1 pixel per cm. Then you would know that a wall that is 1m tall would need to be made at 100 pixels in height. And then calculate your entire model like that. Its a way of ensuring that little postage stamp size faces do not have 2048 x 2048 pixel images applied to them and large building facade faces do not have 64 x 64 pixel images.

                That is my understanding of it all, so forgive me if I'm wrong. I think it is scriptable.

                Chris

                Lately you've been tan, suspicious for the winter.
                All my Plugins I've written

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                • A Offline
                  alz
                  last edited by

                  You got it -- it's the pixel density. So a 1:1 texel ratio would be 1 pixel per 1 unit on the model. So a 256x256 texture at 1:1 would fit exactly on a 256 unit wall (before repeating).

                  This means you could swap the 256x256 texture for 64x64 and you'd see it repeating 4x on the wall.

                  This wouldn't be the Texture width/height in the Material browser, correct? That affects the individual texture and how it's applied to anything in the world. The texel concept is scale applied to the UVs of the object.

                  I'm still wrapping my head around this concept. It seems simple, but I suppose it's confusing at first because I haven't seen a dialog for it readily exposed in any major editor [Max, Maya, SketchUp] (so it's not easy to play around with).

                  --alz

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                  • AdamBA Offline
                    AdamB
                    last edited by

                    alz, Sketchup handles textures in a different (I think better) way to most modellers.

                    The short answer, is that Sketchup does what you want 'right out of the box' because for each texture, you specify how much world space it should cover. Sketchup then ensures that the texture repeats sufficiently to satisfy that "texel density".

                    Just open the material editor and change the Width/Height fields which are World Units (eg meters / feet).

                    My plugin called Goldilocks uses the Sketchup material "texel:world space density" to check whether for a given viewpoint, that density gives a good "texel:pixel density".

                    In other words, Sketchup will automatically texture like your second image.

                    Adam

                    Developer of LightUp Click for website

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                    • A Offline
                      alz
                      last edited by

                      Thanks for the explanation Adam!

                      I suspected this was the case, but was unsure. I didn't know if Texel information was part of the object (meaning you could toss whatever texture you want on it and it'd match the ratio) or if it needs to be specified for each material.

                      SketchUp far more simple and to-the-point than massive programs like 3dsMax!

                      --alz

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                      • A Offline
                        alz
                        last edited by

                        Here's a follow-up question --

                        Let's say I have 10 textures. 1 is 512x512 in resolution, set to 512x512 sketchup units. The other 9 are 256x256 in resolution, set to 256x256 sketchup units.

                        By default, applying all these textures on different sized faces will produce a 1:1 texel ratio.

                        So...
                        How would I make everything 4:1? Would I have to go in to Texture/Position and scale every face?*** Or, is there an option or plugin that can pick the desired scale from a face and transfer it to other faces?

                        ***Texture scaling doesn't have a VCB numeric option for exact sizing? And without a way to display the current scale, there's no way to understand what the current texel ratio is, correct? I wish the "Reset Position" option was actually three options: Reset Position, Scale, or Rotation.

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                        • Chris FullmerC Offline
                          Chris Fullmer
                          last edited by

                          The easiest way to recale so a 1:1 up to 4:1 would be to go into the material browser and just change the dimensions of the material. To get 4 times better texel resolution, change the 512" x 512" to 128" x 128". Then you have 4 pixels per inch in your model. And it will resize the faces accordingly.

                          It will not reset the existing scale applied to any specific face though. But it will multiply on top of that scale. Try it out by making a bunch of faces, add the default scaled material to them. THen change the scale manually on a few of the faces. THen go into the in-model materials and edit the material. You will see how it changes on the default faces and on the faces where the mateerial was manually scaled.

                          Hope that helps,

                          Chris

                          Lately you've been tan, suspicious for the winter.
                          All my Plugins I've written

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                          • A Offline
                            alz
                            last edited by

                            Ah -- yeah I can see what's happening. Thanks for confirming Chris!

                            In large scenes, it'd be easier if there was a global setting or way to transfer one scale to another. If there's 20 or so textures in a scene, that's a lot of material changes to do, heh.

                            For example, you might want to keep the default size for 80% of faces that use the material, but on the other 20% you want a different density. So instead of duplicating the material to change the scale, find a way to simply change the UV scale on the 20%.

                            I'll poke around the web and see if there's something already out there. If not -- maybe it's a good candidate for a plugin.

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                            • Chris FullmerC Offline
                              Chris Fullmer
                              last edited by

                              On a side note, I am realizing my math is sloppy, or possibly mis-leading too.

                              512x512 image at 512"x512" is 1:1.

                              To get to 4:1, if you mean 4 pixels to one square inch, then you actually reduce 512"x512" to 256"x256". That will produce 4 pixels to one square inch. going to 128"x128" will produce 16:1 - 16 pixels per square inch.

                              So don't mess up your math like I did, or you will end up with overly detailed or incorrectly scaled images.

                              Chris

                              Lately you've been tan, suspicious for the winter.
                              All my Plugins I've written

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                              • A Offline
                                alz
                                last edited by

                                haha -- yes -- good point! I had forgotten about the squared aspect as well

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