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Friday, February 20, 2009

Modeling a Y-branch polysurface


Learn how to model a smooth Y shaped polysurface in Rhino using the Sweep1 and BlendSrf commands.

9 comments:

STU said...

another fine tutorial. thanks!

Brian James said...

Thanks STU!
If you have an ideas for future tutorials you'd like to see posted, feel free to suggest them.

Cheers,

STU said...

after playing around, am curious how you could branch 3 or 4 sweeps into on branch.

would you just mirror them radially around a center point and then blend all the side surfaces? any tips?

Brian James said...

Hi STU,
You can sometimes get the method you describe to work by leaving a space between the 3 blended srfs you'd create and using the Patch command to fill it. This is a tricky srf to join however with some shapes. Another approach would be to model a "hub" shape with trimmed holes in it and then blend your swept srf ends into that.

If you have a particular model in question you can always shoot it off to Tech(at)McNeel.com for suggestions. Just remember to "save small" and zip it first.

expansion said...

good to know! cheers

mike said...

but my circles are not always mirror of each other, i may one circles of different radius or even an ellipsie. In these cases, i would be hard to draw the rectangle.

Brian James said...

Hi Mike,
The rectangle used to trim the two swept surfaces can be any curve, either open or closed. The nice thing about blend surface is that it can take multiple edge selections, so where you cut isn't that important... it doesn't have to be a straight cut like shown in the video. If you have a file that you'd like an opinion on, you can send it to "tech(at)mcneel(dot)com".

Thanks,

tseng said...

dear all,

i try to creat a branch, which not just 2 in to 1, but 6 into 1.

in this case I got lot of problem with geometrie to make a smooth fillet/blending between them...

If there are any example I can look?

Thanks you all!!!

best regard


frank, germany

Brian James said...

Although using this technique for more than two branches is possible. There is usually always a small gap where the branches merge that will need to be patched. This can be a tedious work flow as you are discovering. If you do this type of form a lot, I'd suggest looking at the T-splines plugin for Rhino.
http://www.tsplines.com/
This is a great tool for the type of shape you described.