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Re: mesh clipping [message #31872] Tue, 27 August 2002 09:46 Go to previous message
Rick Towler is currently offline  Rick Towler
Messages: 821
Registered: August 1998
Senior Member
"lyubo" <lzagorch@cs.wright.edu> wrote

> In general, can I draw a plane in IDL which will cover the front part of
the
> mesh without clipping it, or is there any other way of doing that?

Sort of. You can set up your view such that it clips your mesh, and then
adjust the eye property until you are viewing it from the deired distance
(or you can adjust the viewplane rectangle, or you can use my camera and
simply adjust the zoom). You may not see what you are expecting depending
on the way your mesh was drawn though.

As for the other way, if you are going to be slicing your mesh up
interactivly *and* your hardware can render your full mesh quickly consider
using an alpha channel to "hide" parts of your mesh instead of removing
them. This should be significantly faster.

As I hinted to above, the order in which the mesh is rendered is very
important when clipping with the view or using alpha blending. You must
draw the mesh starting with your -z verts and draw torwards +z. Google this
group for "Pimento Problems" for the full explanation.

The trick will be setting up your texture_coords...


> Also, why IDLgrVolume is so slow?

Most likely your graphics adapter isn't designed to accelerate the rendering
of volumes.


-Rick
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