Live LSCM Unwrap

  / by Matt

Here’s a nice little demo of a new feature in Blender, added a day or two ago – LSCM Live Transform. When it’s switched on in the UV/Image editor window, it recalculates the LSCM within the transform loop when you’re moving/rotating/scaling pinned vertices, so it gives realtime feedback – a real time saver! It’s a lot more powerful than proportional edit, since it’s properly calculating LSCM using the correct edge angles, adjusting the UV unwrap shape for the best fit.

This should really come in handy when we unwrap and texture our characters very soon! Here’s a little demo video that I did with one of Bassam’s old test characters, the geometry .blend file is linked in this blog post.

mancandy lscm
» divx icon 5MB DivX AVI | mov icon 7MB .mov Animation codec

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23 Responses to “Live LSCM Unwrap”

  1. Mal said on 24 Nov, 2005:

    Excellent work!

    BTW this might be interesting for the developers to have a look at…

    Its a similar op begin carried out in 3DS Max.

    Now, if Blender could only see the update of the textures on the live 3D model in the viewport, that would truely rock!

  2. Matt said on 24 Nov, 2005:

    The Pelt Mapping gives a very nice initial result, but I don’t know how easy it is to tweak once it’s done its thing. It looks like you may be just stuck editing the individual UVs. The great thing about this Live LSCM is that you’ve got a lot of control if the automatic unwrap isn’t perfect, or you want to tweak it. If you’ve got a bit of distortion in an area, you can grab a pinned point and it recalculates properly instead of you trying to match up the bare UVs on your own.

    And of course you can see the textures updating live :) Just click the little ‘Lock’ icon in the UV/Image window header, and it updates the 3D View. This also works in other windows like Ipo, Action, etc. It should probably be turned on by default since nowadays computers are pretty fast. I’m also hoping to commit an option in the Image->New… command to auto-generate a nice UV layout test pattern when a new image is created, for testing distortion.


  3. Rui Campos (RCAS) said on 24 Nov, 2005:

    Computers are fast, but Blender OpenGL implementation on textures make several graphic cards struggle to display it fast.

    So, keeping the 3D View on Textured mode means “slow Blender”. At least in my experience with several cards.

    Maybe Ton gets to fix this when he revamps the material system.

  4. ZanQdo said on 24 Nov, 2005:

    HI, me and my friends have tested lots of UV unwrap methods, (modo, 3D Studio, etc) Blende’s semi automatic LSCM is totally better, LOTS OF CONTROLL!

  5. Rui Campos (RCAS) said on 24 Nov, 2005:

    The only thing I see missing on the LSCM Unwrap with regards to Pelt Mapping is the ability to relax the unwrapped mesh so it fits more nicely into the model.
    Other then that, I like it better then Pelt Mapping, but thats just me.


  6. DS said on 25 Nov, 2005:

    Is it possible to copy uvs from one model to another if they have the same vertices?– So you have smooth the model first do the uvs and them copy it too your original model.

    This looks awesome – handy new feature indeed.

  7. Jonathan Merritt said on 25 Nov, 2005:

    Wow! This is awesome. I have a model of a canine pelvis for which I spent ages tweaking the UV coords. I can now re-do about 30 minutes work in 30 seconds. Fantastic! :-)

  8. deal_maker said on 25 Nov, 2005:

    Looks like an add that was on for Modo. I like the look of it. Well done!

    (I have the right post this time.)

  9. ZanQdo said on 25 Nov, 2005:

    “Looks like an add that was on for Modo”

    Thats what I’m sayng, modo only work in the adds, not in real life XD

  10. Messiah said on 25 Nov, 2005:

    Wow ! That’s very impressive ! This will speed up the UV making by far. Though, do you think that implementing a mirror editing tool in the UV editor wouldn’t be great too ?
    Keep on the great job !

  11. Disho said on 25 Nov, 2005:

    WOWWWW! This is not an eye candy! Very useful. I managed to make UVUnwrap Suzanne in a minute. Something I never done before.
    Great control over result. Definetly better than pelt!
    Thank you developers!

  12. William said on 26 Nov, 2005:

    Is there as to leave the LSCM Unwrap individual for each mesh?

  13. Rui Campos (RCAS) said on 26 Nov, 2005:

    A thing that should be added is a checkerboard as default image if no image is loaded, so we can see how the Unwrap is coming along.

    Also a nice feature would be to relax the Unwrap (something like in Pelt Mapping video) that would make the “checkerboard” be distributed more evenly, outputing a better UVMap for painting.


    — Rui —

  14. Matt said on 26 Nov, 2005:

    Rui: I have a patch in the patch tracker that adds the option to generate a coloured checkerboard UV test pattern in the Image->New… command. Hopefully it will make it in before release. A Relax function would be nice, especially for overlapping areas. I think Brecht had an ‘optimise stretch’ function way back in tuhopuu2, but I haven’t heard what happened to that.

    However it’s not nearly as necessary with LSCM as it is with Pelt, since LSCM does a pretty good job of minimising distortion. Pelt mapping can really distort the layout (large UV polys on the outside near where it’s being stretched from, with small polys inside) so relaxation is almost always necessary.

  15. AniCator said on 26 Nov, 2005:

    nice feature

  16. Blazer003 said on 26 Nov, 2005:

    This is quite simply revolutionary. Amazing. (Blazer goes back to remap poorly unwrapped models)

  17. Roger said on 27 Nov, 2005:

    great feature! It seems to me that the UV editor is fast becoming just like the mesh editor – the UV map always reminded me of a dense mesh plane; in fact, early blender descriptions called it just that (UV was used instead of XY because there is no Z). Perhaps there could be code sharing and labor saving if the same tools could be used (proportional edit, scale, rotate, grab, push, pull) on either a UV mesh or a dense mesh. I’m thinking a push tool on a UV mesh would ‘draw in’ the vertices around the selected, like you would see a cloth do if your pushed it through a hole in the table. In the video example, instead of grabbing on points in the pelt to rotate it, a simple A-key, R-key, mouse move around the center would do the same thing. In fact, then, cutting tool could be used to add faces.

  18. Kyle Dell'Aquila said on 27 Nov, 2005:

    wooahh!… UV wraping is getting a step easier again! Kinda reminds me of Modo’s UV unwraping system. “Drag and click!”

  19. Rui Campos (RCAS) said on 27 Nov, 2005:

    Matt: Great :) .

  20. Matt said on 27 Nov, 2005:

    Roger: The UV editor already behaves similarly to the mesh editing, and as far as I know after the transform code rewrite in 2.37 it does share a lot of the code. You can already use nearly all of the same transform tools, move, rotate, scale, proportional, align, mirror, etc. – it’s all in the UVs menu ;) I don’t know what you mean by a cutting tool – you can’t cut UVs, since they’re connected to the topology of the mesh. You can’t cut UV faces without cutting the mesh faces themselves.

    Edit: Oh and rcas, brecht commited the test pattern patch today :) find it in Image->New…

  21. Rui Campos said on 28 Nov, 2005:

    Matt: saw that, great.

  22. Uto said on 18 Dec, 2005:

    This is so sweet!

  23. Peter Crisp said on 22 Apr, 2006:

    Can this UV unwrap tool be used to unfold 3D meshes into 2D patterns for making real objects? I’ve been looking at Blender and Wings3D for this purpose.