 | | Re: Why Type 5 Lines?
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I was reading through this more, and while I still don't know exactly how it all works, I think I stumbled onto something. > I dont know how many of you have come across this technique before. I > remember finding an OpenGL demo that did this kind (...) (23 years ago, 18-Apr-02, to lugnet.cad.dev)
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| | Re: Why Type 5 Lines?
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(...) One problem: transparent surfaces would show the wireframe backside. :\ Steve (23 years ago, 18-Apr-02, to lugnet.cad.dev)
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| | Re: Why Type 5 Lines?
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(...) Actually, transparent surface should work fine. As long as they are set to write to the Z buffer when drawn, and their outlines are drawn with Z buffer testing enabled, they should work fine. The wireframe parts that aren't supposed to be (...) (23 years ago, 18-Apr-02, to lugnet.cad.dev)
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| | Re: Why Type 5 Lines?
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(...) The backside wireframe elements *will* be drawn, that's the point of what Kyle was talking about. The idea is to draw the wireframe of the backside surfaces and it will all be hidden by the frontside surfaces, *except* for the lines around the (...) (23 years ago, 19-Apr-02, to lugnet.cad.dev)
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| | Re: Why Type 5 Lines?
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(...) I understand what you are saying, but it won't happen that way if Z buffer writing is enabled during the drawing of the transparent surfaces. The transparent surfaces aren't really transparent. They're just blended with whatever is behind (...) (23 years ago, 19-Apr-02, to lugnet.cad.dev)
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| | Re: Why Type 5 Lines?
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(...) Cool. Thanks for taking the time to explain it to me. I didn't realize this about opengl. Steve "please speak slowly and clearly" Bliss (23 years ago, 19-Apr-02, to lugnet.cad.dev)
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| | Re: Alternate Type 5 line algorithm and other BFC questions...
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[snip] > > Normally you don't bother to enable Z buffer writing when drawing the > transparent surfaces, because they are the last thing drawn, and it won't > matter. However, it doesn't hurt anything to enable it, other than slowing > it down a (...) (23 years ago, 19-Apr-02, to lugnet.cad.dev)
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| | Re: Why Type 5 Lines?
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(...) Thanks for that explanation, however I think we still need to include type 5 lines in parts, so that programs which don't implement this technique (eg ldraw) can still display the curved edges correctly. Programs which do implement it can (...) (23 years ago, 19-Apr-02, to lugnet.cad.dev)
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| | Re: Alternate Type 5 line algorithm and other BFC questions...
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(...) Just check to see if the determinant of the matrix is negative. If it is, the matrix involves mirroring. --Travis Cobbs (tcobbs@REMOVE.halibut.com) (23 years ago, 19-Apr-02, to lugnet.cad.dev)
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| | Re: Why Type 5 Lines?
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(...) Sorry, I never intended to imply that it should replace type 5 lines. In addition to the problem of backwards compatibility, this will only work for BFC-certified parts. --Travis Cobbs (tcobbs@REMOVE.halibut.com) (23 years ago, 19-Apr-02, to lugnet.cad.dev)
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