View Full Version : MR - displacement to poly

12 December 2006, 11:09 AM
hi all,

i want to convert the displacement mapping into actual polygons. maya already has that option, however it uses the software mode for that i think, it ends up really messy and incorrect. i would like to have the same effect created by the MR Approximation Editor. Is there any way to do that, and how?

thanks in advance

12 December 2006, 02:49 PM
humm..I don't think that is possible

since all the tesselation happends in render time... :shrug:

12 December 2006, 12:54 PM
That was found under the Mesh node documentation (Maya):

userTrg (utrg) string NULL

The name of the user defined face triangulation function. By defualt, it is an empty string, which means Maya face triangulation will be used. Users can override the default triangulation by setting this attribute to the name of their own function registered with Maya through the API.
Could by any chance mr approx nodes belong to that category ? Could someone experienced give it a try ? I would be very interested in such a feature too... who would not ?


12 December 2006, 12:44 AM
BTW, if you have a standalone pipeline, there is a way to remake your mi file to contain pre-displaced objects.

The -echo option to ray has a mode to echo the approximated geometry back into the file. Ex. ray -echo tesselated.mi approx -- original.mi

This means that you should turn the displacement off when rendering the remade mi file, or you'll get twice the displacement. Ex. ray -displace off tesselated.mi

12 December 2006, 01:49 AM
Mmm interesting... but is there a way to extract the geometry from the mi file anyway ?

12 December 2006, 11:17 PM
On export to mi files, the object has what is called 'source geometry', before any approximation method has been applied to create the tessellated renderable geometry. Using the -echo approx command above, it can apply your approximation to store a polygonal post-approximation tessellated version of the geometry as the source geometry in the echoed mi file.

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12 December 2006, 11:17 PM
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