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smooth groups and normals

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Hi, I'm doing a little research on the different approaches to process mesh normals. So far, I found that 3DSMax uses smooth groups. Smooth groups are also defined in the 3DS and OBJ file formats, so they could be considered more or less, standard. But other programs do not use smooth groups at all: for example, Lightwave simply uses a "max angle" for the whole mesh, so you have little control over how the normals are generated. I know this is a question more intended for artists, but since my objective is to develop normal computation algorithms, I think my question still fits here: What other programs like Blender, SoftImage or Maya, use to allow designers adjust the normals over a mesh? do they use smooth groups also? or do they use something completely different? Thanks in advance!

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I'm no designer, but my brother is one. He's working with blender. If I've understood him correctly, then in blender you can smooth each individual face, and each transition between adjacent smooth faces is then computed with normal interpolation. This is a kind of smooth group, I think.

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Quote:
Original post by Guntharpo
In Maya you harden and soften edges.


Looks like maya has the most designer-friendly method!

Anyone know what Softimage uses?



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Quote:
Original post by haegarr
If I've understood him correctly, then in blender you can smooth each individual face, and each transition between adjacent smooth faces is then computed with normal interpolation. This is a kind of smooth group, I think.
Yes, but real smooth groups also let you make a "hard edge" within a smooth area. Blender lets you get that effect too, by hitting YKEY (split). "Rem dbl" to remove the smooth group.
While Blender doesn't natively support (yet?) the concept of smoothing groups, splitting is the exact same thing from a technical point of view (only a tiny bit less comfortable).

In fact, splitting is so useful that I'm always smooth shading everything now, and split straight faces that should have a "flatshaded" look, because for coplanar triangles, it uses less vertices for a visually equivalent effect.

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