 | | | Texture Projection problem with Displacement | Texture Projection problem with Displacement 2004-06-24 - By Morten Bartholdy
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Hi people,
I have this rather big ocean with a ship creating bow wakes. I use procedurally
generated displacement for waves and want to use displacement for the bow wake
also for practical reasons, given the size of the ocean and geometric detail
needed to do it with deformation techniques.
I use a smaller texture for the bow wake, and want to position and animate it
to follow the ship, animating the position of the Texture Projection. The
displacement map has 50% gray for neutral height, white going up and black
going down. I use change range to offset the displacement appropriately, which
works fine inside of the texture, but not outside the Projection, where it seem
mental ray thinks I have black instead of no texture...
See what I mean here - it is a testbench scene:
http://colorshopvfx.dk/XSI/Texture_Projection_prob.jpg
I would have thought the displacement map should not affect the geometry
outside of the projection, but it seems it does, and I did try scaling the
Support with similar results.
Is this just the way MR behaves or is there a clever workaround?
I'd rather not make my texture map big enough to fit the geometry animating the
bow wakes as a texture sequence, so I'll really appreciate good ideas.
TIA!
--
Morten Bartholdy | morten@(protected)
Denmark
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<DIV><FONT face=Arial size=2>Hi people,</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I have this rather big ocean with a ship creating
bow wakes. I use procedurally generated displacement for waves and want to use
displacement for the bow wake also for practical reasons, given the size of the
ocean and geometric detail needed to do it with deformation
techniques.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I use a smaller texture for the bow wake, and want
to position and animate it to follow the ship, animating the position
of the Texture Projection. The displacement map has 50% gray for neutral
height, white going up and black going down. I use change range to offset the
displacement appropriately, which works fine inside of the texture, but not
outside the Projection, where it seem mental ray thinks I have black instead of
no texture...</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>See what I mean here - it is a testbench
scene:</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2><A
href="http://colorshopvfx.dk/XSI/Texture_Projection_prob.jpg">http:/
/colorshopvfx.dk/XSI/Texture_Projection_prob.jpg</A></FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I would have thought the displacement map should
not affect the geometry outside of the projection, but it seems it does, and I
did try scaling the Support with similar results.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Is this just the way MR behaves or is there a
clever workaround?</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I'd rather not make my texture map big enough to
fit the geometry animating the bow wakes as a texture sequence, so I'll really
appreciate good ideas.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>TIA!</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>--</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>Morten Bartholdy | <A
href="mailto:morten@(protected)">morten@(protected)</A><BR>Denmark<
/FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV></BODY></HTML>
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