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Smooth vs Smooth Edges / Crease Edges vs Smooth/Crease Tool ?
Posted: 05 December 2012 12:46 PM   [ Ignore ]
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For organic models (people, hair props, clothes, animals, etc) I usually take a quick trip to the Vertix Modeller and select all and turn on the SMOOTH function. This almost always makes the model look better.

However, on architecture and mechanical objects this is sometimes a disaster and sometimes not. I try to start in with selecting specific facets (usually via Select By…—> Domain Name) and then I attempt to use the Smooth Edges… / Crease Edges… function under the MODEL menu, But things often go wonky leaving me with areas that are worse looking than when the model is first imported. Flat areas are usually easy to define and Crease, but rounded meshes fringe at the edges of the mesh, and don’t always Smooth in expected ways. Often each triangle ends up looking puffy and causing shadow/highlight issues, or showing an apparent curve the wrong way (inverted or dented).

How can I fix this? Or should I avoid it altogether? Some of the worst problems occur at the edges of an “unclosed” mesh. Other issues seem to be that after i apply smoothing, the facets along a curve might look worse (perhaps the normals need to be flipped?)

Are there any rules of thumb? Should I just live with faceted curves? Would increasing the subdivision be a better solution? Should smooth and subdivision be used together or will that just add more facets?

Also There is a Crease/Smooth Icon but I have no idea what it does… Any tips?

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Posted: 05 December 2012 02:35 PM   [ Ignore ]   [ # 1 ]
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it’s often better to do a pair of offset edges from the edge in question instead of using functions like smooth/crease. The smoothing can then be controlled by exactly how far off the edge the offset edges are. This is usually more stable and will allow transferring an object to another environment which functions like smooth/crease edges won’t usually. As for normal direction, I’m not sure what the function is in Carrara is, but there is usually a tool which will show the direction of normals via a line out from the normal face. Also, flipped normals will look invisible from the back face if they aren’t double sided. Some tools (again, not sure about Carrara, but in Blender for instance) have a function to automatically fix flipped normals.

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Posted: 05 December 2012 02:46 PM   [ Ignore ]   [ # 2 ]
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It depends on how the model is constructed.

Often in older poser models (and new ones too come to think of it), any ‘box’ is made of seperate planes unwelded instead of one whole mesh. When you apply smoothing to that it turns into unconnected circles. The bulk creasing can help with this if you play with the angle but it usually misses some things. You need to make sure that the edges of unconnected planes are creased to force them to stay flat.

The only guaranteed way to get everything as you want it is to crease each edge individually using the crease/smooth tool, the icon that you have mentoned. (click on an edge to crease it, ctrl (cmnd) click on the edge to smooth)

If it’s a prop without morphs you may be able to weld (use custom tolerance and make sure it’s low enough) and then try to crease edges.

It can take a lot of patience depending on how complicated the model is but you can skip anything that’s not going to be seen. It’s often worth it in the end to turn a scene filler model into something good enough for a close-up (after you’ve updated the texture too of course)

The normals are probably ok. Straight Subdivision from the menu will simply give more polys without any smoothing applied. If you want to see how SubD smoothing is working simply click on ‘Convert’ to see the converted mesh. Remember to undo straight away. (Don’t try this on too high a level or too detailed a mesh). Once you do that a few times with creased and smoothed edges you will understand how the smoothing pulls vertexes around and it will help you decide where to place the creases.

Increasing the smoothing level on an already badly smoothed model will make it worse.

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Posted: 05 December 2012 02:49 PM   [ Ignore ]   [ # 3 ]
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Yes my post was (mistakenly assuming) a connected mesh.

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Posted: 05 December 2012 03:09 PM   [ Ignore ]   [ # 4 ]
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Thank you both… Reading carefully I think I also realize another mistake I was making… I always think a mesh is filled polygons, but you make me realize this tool is all about EDGES…. When I select a poly and use the menu to smooth or crease, it is creasing or smoothing all the edges and into the adjacent polygons…. *smack hand on forehead* Of course! This is why I get “weird” results… Ugh, ok I’m an idiot. Especially since the menu function is called Smooth EDGES…
red face

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Posted: 05 December 2012 03:10 PM   [ Ignore ]   [ # 5 ]
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Yes, you want to select ‘an edge’ when smoothing. Actually though, making the jump to thinking of a mesh as edges/polys/verts depending on the context and switching easily between the three, how modifying in one mode effects the others, etc… is a step towards a much fuller understanding of meshes. In some programs one can ‘extrude’ verts for instance, and it has valid applications wink

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