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# 1 25-09-2009 , 04:23 PM
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Maya polygon extrusion

Hi, I'm gradually trying to switch from Lightwave to Maya, but I found several odd behaviours and things that are so different that I cannot figure out.

For example, extrusion works differently from Lightwave and other 3d packages I used: when I extrude a polygon, Lightwave actually duplicates the selected polygon and extrudes it along the axis. In Maya, the polygon is not duplicated, it's just moved along the path.
So my question is: how do you actually duplicate geometry, if extrusion works this way ?

Another issue is that there is no way to use live simmetry (modify a simmetrycal model without having to duplicate and mirror the geometry), unless some extra commercial plugins like DigitalRaster Nex.

Thanks for any hint ... :bow:

# 2 25-09-2009 , 04:40 PM
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You can modify symmetrically by enabling reflection in your tool options. As for duplicating the polygons, I haven't used Lightwave, so I'm entirely sure what you mean.

# 3 25-09-2009 , 04:53 PM
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Ok here is an image: you see that in LW, extrusion actually duplicates the polygon too, while Maya doesn't (see the hole).

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# 4 25-09-2009 , 04:57 PM
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doesn't that create non-manifold geometry?

just use the apend tool to fix it.

# 5 25-09-2009 , 05:00 PM
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Yeah, maya seems to have a better implementation here. Extrude in maya results in a surface that contains edges that only border at most two faces, so the mesh can easily be represented in two dimensions, by "flattening" it all out.

# 6 25-09-2009 , 05:02 PM
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Ok, but say you extrude 200 polygons all at once: I'd rather not have to create manually the 200 ones missing...

# 7 25-09-2009 , 05:05 PM
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Also, about simmetry, enabling reflection allows to move, scale or rotate polygons, but you cannot delete or extrude them ... user added image

# 8 25-09-2009 , 05:19 PM
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extract the faces, then extrude, then combine and merge the verts... dunno why you would want to tho

user added image

# 9 25-09-2009 , 05:21 PM
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Don't know for sure, but I think a mirrored instance of your geometry should allow you to keep current all necessary changes including extruding.

Not sure what you need the "missing" faces for... is it for the back side of your mesh?? You should really only have one "side" to your mesh; i.e. make it three dimensional, inside being unseen, if that makes sense.

# 10 25-09-2009 , 05:26 PM
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I got the same problem, can someone help me out, see the image, that is my extrution

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# 11 25-09-2009 , 05:35 PM
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problem solved for me, that is the solution,

it is duplicate vertex on each others, go to component mode, I mean right mouse click and select vertex. than try select all the vertex around the hole one by one and merge and merge it, now try extrude face again , see if changed or the way that you want.

# 12 25-09-2009 , 05:47 PM
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you could just use the apend tool.

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