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Old 21st November 2003, 12:22 AM   #1
Cowboybebop
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Default What causes holes in your models ?

Like If your moving vertices around and then a face disappears ? Outlined by red lines, funny thing is they aren't really gone they just appear to be in 3d view but moving the vertices back brings it back and sometimes moving it further up brings the face back as well. What exactly is happening ?
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Old 21st November 2003, 03:19 AM   #2
Andy
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Default Re: What causes holes in your models ?

When a polygon turns into a red outline, it means that it's invalid. This is because it either has edges that cross over or it's non-planar.

Trangulating the polygon will usually prevent this happening (since triangles are always planar and can't have crossed edges.

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Old 21st November 2003, 03:27 AM   #3
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Default Re: What causes holes in your models ?

Yeah, what he said.
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Old 21st November 2003, 05:59 AM   #4
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Default Re: What causes holes in your models ?

what's none planar ?
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Old 21st November 2003, 06:14 AM   #5
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Default Re: What causes holes in your models ?

Make a rectangle in the plan view. Select one vertex and pull it upwards in the front view. Now all points are not on the same plane. Although AC3D copes quite well with this shape, this non-planar rectangle should really be triangulated since all the points are not 'flat' on the same plane.

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Old 21st November 2003, 10:58 AM   #6
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Default Re: What causes holes in your models ?

Andy,

Do you think in the future versions you can have an option to automatically triangulate non-planar polygons?
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Old 21st November 2003, 11:26 AM   #7
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Default Re: What causes holes in your models ?

>Do you think in the future versions you can have an option to automatically triangulate non-planar polygons?

I think adding a function that selected the surfaces that were non-planar would be more useful.

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Old 21st November 2003, 12:10 PM   #8
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Default Re: What causes holes in your models ?

I thought this was such a good idea that there now a plugin to select non-planar surfaces:

Please try it out:

www.ac3d.org/ac3d/temp/select_nonplanar.zip

(unzip and put in plugins folder)

It adds a menu item to the tools menu.

Let me me know how you get on.

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Old 21st November 2003, 12:23 PM   #9
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Default Re: What causes holes in your models ?

Andy,

I tried it out. Works great.

My question is why allow us to make non-planar polygons. I used to have a old 3d program (for the Amiga computer) that won't allow it.
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Old 21st November 2003, 02:03 PM   #10
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Default Re: What causes holes in your models ?

A surface is just a list of vertices and they can be anywhere and could be a line.

I don't believe imposing a restriction would be nice - far better to be able to detect them (if needed).

They do not matter for some models and for some destination file formats. If you are modeling with subdivisions, you can get nice (material like) shapes with non-planar polygons.

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