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Blending geometry intersections?

Hello everyone,

I'm struggling with the following problem: https://www.dropbox.com/s/rk6pkcoeueqau57/TreeIntersections.JPG?dl=0.

As you can see, the intersections of the branches - which are pushed together and overlapping - have really bad lighting. I tried to fix this by manually adjusting the vertex normals, but apart from the task being cumbersone and time-consuming, I just couldn't get a good result. Are there any solutions to this?

Thanks in advance!

Nicolas

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  • Kurt Russell Fan Club
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    Kurt Russell Fan Club polycounter lvl 9
    Is this in an engine or rendered in a 3d application? It could be that you're using vertex lighting so vertices embedded in the tree don't get lit, which would make them dark. It's not a great image with the jpeg compression and dark lighting so maybe another shot at higher quality would help (you can upload to imgur and link the image directly)
  • Klunk
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    Klunk ngon master
    Are there any solutions to this?

    the obvious one is not to use intersecting meshes and stitch the geometry together although it's time consuming and adds to face and vert counts
  • sprunghunt
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    sprunghunt polycounter
    Klunk wrote: »
    the obvious one is not to use intersecting meshes and stitch the geometry together although it's time consuming and adds to face and vert counts

    If you were to use a blended depth shader to hide the geometry intersections you'd run into extra overdraw on the trunk area. This would probably be a much bigger performance hit than extra vertexes.
  • Latiro
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    Thanks for the answers! :)

    I will get a higher quality shot as soon as possible, though I don't think there's a lot more to be seen than what's on the screenshot. Might it help to "snap" the vertices on the intersection onto each other? Right now the branch border is pushed kind of far into the trunk. Maybe if I would snap the vertices onto each other, could that solve the problem?
  • Klunk
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    Klunk ngon master
    though it is possible to improve intersecting geometry

    [ame]http://www.youtube.com/watch?v=saDwhoBJbTY[/ame]

    it requires some custom tools to handle or a lot of manual tweaking using the standard tools so I still think if it's a real issue cut and stitch is still the best option
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