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I'm starting to get into subD and I want to create a try to hold some product.  I have it mostly modeled out and I like the curvature of the model with the sharpness at 50%, but I'm getting some pretty jagged corners and I'm not sure how to address these.  Any input would be helpful.


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Just a quick glance tells me it's all those triangles in your mesh.

In general, I try to avoid them in favor of 4 side polygons.

I am slammed today but tomorrow I might get time to fiddle with it.

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You can try increasing the number of Iterations to 5 or 6.  


Ultimately, You will need to rework some of the geometry modeling though.  The base has some very strange corners and they will need to be rebuilt front scratch before you can get nice smooth corners.  


Looking at the model, I wouldn't necessarily use SubD for this.  You can get nice smooth results using solid modeling, and controlled rounding.  

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yeah the base is where I'm having the problems.  I'll rework the cage model so get some better results.


I tried creating this shape with NURBS but SubD seemed to be a much faster alternative.


This tray is going to be made with a mold and vacuum-formed plastic so I don't think controlled rounding is going to give me the "flowy" appearance that I want.

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I am 100% certain your problems are caused by the triangulated geometry.

I realize that in a couple of the sub-d tutorials FZ shows using triangles,

but I never use them for 2 main reasons:


1. They tend to cause “pinched” geometry (especially on corners and edges).

2. You can’t sub-divide triangles any further, so you essentially paint yourself into a corner.


I have attached a little guide that I did for one of my co-workers, to help them understand what

causes triangles and how to avoid them. Maybe it will be of help to you.



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FZnoob is correct that you need to be aware of the number of sides in your faces, however what is most important is to avoid having faces with more than 4 edges. At its heart subD's can only work with triangles and quads so formZ has to breakup the model to handle any faces with more than 4 sides. This gives you very little control with what happens with these faces. Its better to clean the yourself to get predictable results. Note that sometimes face may look like it only has 4 sides, but if an edge of an adjacent face touches an edge of a give face forming a "T" intersection, then the that face will have and additional point to maintain the connection. This is the case with the "large angled face" of the model. (see attached).


Here is what we did with your model to get better results:


1. We noticed that you have some probably unintended unclean intersection at two of the corners. We cleaned this up with the Delete topology tool (see image).

2 .We used the object doctor to clean up the model some more (extra co-linear edges etc...).

3. We used the insert segment tool (along with the perpendicular snap) to add edges that traverse the "large angled face. Note that these need to "wrap" all the way under the model to the other side to avoid creating a bottom face with more than 4 sides! we just kept inserting segments around the model to get the result using the point and perpendicular snaps.


See the attached image for the results this achieved (top line).


Once you have the model in clean triangles and quads, you can use operations line the trinm tool with the stitch option to add detail witch will affect the SubD form. In this example we used a plane and the trim and stitch tool to add a line of detail through the model. Notice the effect on the resulting subD! (bottom line).


We have attached our model as well.


We hope this helps!





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