Wolfgang Dobler:
|Randall Hopper writes:
| > I'm not sure but I think VRML's in the same boat. You could repeat
| > geometry with different colors using backface culling (solid TRUE), but
| > it's a hack.
|
|I don't understand what you mean with `solid TRUE'. Does this refer to DX
|(I can find neither `solid' in this sense, nor even the term `backface
|culling' in the docs) or to VRML? Please bear with my ignorance, as I am
|hardly familiar with VRML and just use it to eventually import DX objects
|into Povray.
It's a VRMLism. I'm not a VRML expert either BTW. I've just picked
through them on occasion to convert them into DX format ;-) Here, check out
the third paragraph here:
http://www.vrml.org/Specifications/VRML97/part1/concepts.html#4.6.3.4
|I am probably too conservative to switch renderers, now that I can do a
|few basic things in this one (Povray). For my application, I have solved
|the problem by a macro that draws the Ribbon twice, displacing it once
|with RubberSheet. [I have no clue what field the RubberSheet deforms here,
|but it works; I suppose one could also shift the ribbon with Compute,
|using the FaceNormals to get the direction.]
It uses "data" to displace "positions" along the normal, or (if not
present) a normal-like direction derived from positions. You may want to
eat least run your data through a Compute("1") and check your normals
before you Rubbersheet to verify you're not doing something wild that'll
distort your ribbons.
Randy
--
Randall Hopper (mailto:[EMAIL PROTECTED])
Lockheed Martin Operation Support
EPA Scientific Visualization Center
US EPA N127-01; RTP, NC 27711
