I need help with NURBS

# 1 27-12-2012 , 05:49 PM

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Join Date: Dec 2012

Posts: 3

So here's my problem, I need to do a Dinosaur's head for a class and i have some problem. when I render my dino i can see every separation of the head even with global stitch set at normal and I don't know why can some help me please?

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# 2 27-12-2012 , 06:25 PM

Lead Modeler - Framestore
Join Date: Feb 2003

Location: UK

Posts: 6,287

Personally I would use attach surfaces instead of global stitch. Global has always been a bit arsey to use.

as a quick way out -you could convert to poly and then combine polys and merge verts

Jay

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# 3 27-12-2012 , 09:07 PM

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Join Date: Jan 2004

Location: Michigan, USA

Posts: 2,998

The gaps you are seeing are most likely due to the default render tessellation being too course.

For nurbs I would recommend always using mental ray. Then attach a mental ray tesslation approximation node to each nurbs surface. There are a lot of options but the fastest and easiest is to select Spacial and set the length to a small value (relative to the scene).

I don't know the scale of your dino but guessing I'd say try .1 unit to start.

I did a video to demonstrate using the nurb tessellation approximation node someplace. I'll try to find it.

howto - use the mr nurbs tesselation approx node.mp4 - YouTube

The video has to do with splitting a sphere into sections and then applying a material to each section but at render time there are visible gaps between the sections (which is what I believe you are seeing).

So follow the video and creating a nurbs tessellation approximation should clean up those gaps you are seeing in your model when rendered.

"If I have seen further it is by standing on the shoulders of giants." Sir Isaac Newton, 1675

Last edited by ctbram; 28-12-2012 at 12:09 AM.

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# 4 27-12-2012 , 09:11 PM

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Join Date: Dec 2012

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attach surface doesn't work and i can't convert in poly because I need to give my project in nurbs

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# 5 27-12-2012 , 09:16 PM

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Join Date: Jan 2004

Location: Michigan, USA

Posts: 2,998

render in mental ray and add a nurbs tessellation approximation node each surface. If it's for a class and you only need a single render you can make the length very small and max subdivisions 6 or 7 and there should be no gaps

"If I have seen further it is by standing on the shoulders of giants." Sir Isaac Newton, 1675

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