#Release 2 Raytracing?
5 messages in this thread
About raytracing. Your approach is really teriffic on shadows, and
reflections…..but refractions ? Think about a clever way to solve
refractions.
TNX Buck
We've actually come up with a very interesting way to simulate refractions
as much as possible with a Phong-shading renderer. Release 2 of 3DS has a
new feature in the materials editor called Transparency Falloff. This
allows you to set the transparency of an object based on the angle of
incidence between the surface normal and the camera.
For example, if you have Trans Falloff set to 100% OUTSIDE on a sphere, the
border of the sphere would be 100% transparent because those surface
normals are facing 90-degrees away from the camera. If you set it to 100%
INSIDE, the center of the sphere would be 100% transparent and the border
of the sphere would be 100% opaque.
This technique doesn't allow optical refractive effects, but it DOES let
you simulate atmospheres, glass opacity effects, soap-bubble type materials
and many more complex transparent objects.
It's extremely effective, and alot of fun to experiment with.
Plus, of course, it's MASSIVELY faster than raytracing. And when you've
got to meet deadlines and do multiple itterations on a project, you need
the speed. Even for stills if you're rendering large images for print.
Speed is speed. Time is money. And deadlines are deadlines.
– G
Thanks for the hint on Falloff in r2. I'm looking forward to getting r2.
To produce refractions, it seems to me you could use a projection technique
like you use now for shadows and reflections…Map the scene that would be
shown through-the-front-surface, to the front surface. Produce a spherical
virtual surface added to the front surface. The spherical parameters are
related to the distance from the front to the back of the object. I mocked
this up a few weeks ago to simulate refraction on a fish tank. I made a
.flc by masking the scene, blocking with an unlit front wall. I then
projected it on a warped front surface. It was too tedious to get perfect,
I should have Morphed the front mesh. It also would probably be easier on a
symetrical object. BUT it was going in the right way.
TNX Buck
Interesting idea. You might also try putting a bump map on a transparent
surface. The transparency will be "perturbed" by the bump and it'll help
to create a refractive illusion.
– G
That's what I forgot to ask about! Refractions! I was wondering about how
to simulate something like that. Even simple glass is hard to make without
refraction. Upping the trasparency of the material just doesn't cut it.
It looks kinda like it's just fading away into air, instead of like glass.
Aaron