Integrating 3D models with photography
Interested in integrating your 3D work with the real world? This might help
# 1 20-09-2002 , 05:12 PM
adldesigner's Avatar
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Tips ... on non-manifold

Well ..after reading a bit through Maya´s docs I came cross this little gem of info when modeling polygons .. and it should help you save trouble also. (Like i did when modeling my sub)


2-manifold topology basically means you can unfold the geometry so that it lies flat on a plane without overlapping pieces.

In the first example (the "T" shape), more than two faces share an edge.

In the second example (the "bowtie" shape), two faces share a single vertex without also sharing an edge. This shape is also possible where two three-dimensional shapes share a vertex (such as two cubes meeting at a single point).

In the third example, a single shape has non-contiguous normals (without border edges). This is a less obvious example of nonmanifold geometry.

The following operations can produce nonmanifold geometry:

Extrude Edge
Normals > Reverse (reverse normals without extracting geometry)
Merge Vertices
Delete Face (select the face and press the backspace key)
Collapse (Face or Edge)
To keep the polygon count down and make tasks such as mapping textures to your objects much easier and quicker, make the pieces of polygonal geometry making up a model fit properly. Avoid creating a polygonal edge that has no face. Also, try to create your polygons so that their normals point in the same direction. Although it is technically valid for the normals to point in opposite directions, textures may not behave as expected.

# 2 20-09-2002 , 05:55 PM
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Nice info there, thanks user added image

Darkon


Red bellows of flame have blackened my stones
Convulsing my frame and cracking my bones
Hell's dragons of steel who roar in their chains
Crawl into my caves to suck out my veins.....

-The Mountain P.F.M.
# 3 20-09-2002 , 06:16 PM
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Yeap .. I was making the second model of the sub .. and even though I even published it here ... I´m not entirely happy with it since ... it has non-mainfold geometry! a pain in the *ss to bevel ... so i decided to see what the hell was causing all the trouble.

Turns out I used Extrude Edge and Merge Vertices to actually fill holes i would carve out from the sub itself. There´s my problem.

So I´m working on a new "version" of the same model but with 2-manifold geometry.

Thanks for the feedback.

# 4 20-09-2002 , 06:54 PM
Kevin
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very nice work there mate!

good lad user added image

# 5 20-09-2002 , 07:09 PM
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nice of you man.. :p

# 6 20-09-2002 , 07:34 PM
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Thanks for the feedback guys!

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