Text archives Help
- From: "Bo Huang" <
>
- To: <
>
- Subject: [Manta] Path tracer & Materials questions
- Date: Thu, 18 Mar 2010 16:45:02 -0400
Seeing some interests in more advanced rendering in other thread, I will
bring up some questions and observations regarding the path tracer and few
materials.
-The ShadowAlgorithm samples AreaLight randomly in respect to its pdf. This
is inefficient for materials such as conductors, and perhaps would rarely
yield correct result. Perhaps we need send some hints to the ShadowAlgorithm
for perfectly specular materials?
-I cannot get any area light itself to render because the path tracer ignores
emmissive contribution. I understand we do not want to intersect geometry
with emissive material because the direct lighting process at the current end
vertex of a path is solely responsible for lighting. Hence I am hesitant to
change it.
Other little things include:
-The path tracer treats all importance terms as diffuse. That is, after
combining the calculations in the path tracer's traceEyeRay(), the material's
sampleBSDF(), and possibly AreaLight's sampling function, each (brdf*cos)/pdf
term in the path integral evaluates to (c*cos)/pdf, where c is the diffuse
reflectance.
-What type of material is considered ThinDielectric? How is the Radiative
Transfer equation modified? Is this related to the Kubelka-Munk model?
-For the Dielectric material attenuation function should be exp() instead of
Pow() right?
-The volume material's code is hard to read. What techniques/papers is it
based on?
Thanks
Bo
The information contained in this e-mail and any accompanying attachments may
contain information that is privileged, confidential or otherwise protected
from disclosure. If you are not the intended recipient of this message, or if
this message has been addressed to you in error, please immediately alert the
sender by reply e-mail and then delete this message and any attachments. Any
dissemination, distribution or other use of the contents of this message by
anyone other than the intended recipient is strictly prohibited. The company
accepts no liability for any damage caused by any virus transmitted by this
email or any attachments.
- [Manta] Path tracer & Materials questions, Bo Huang, 03/18/2010
Archive powered by MHonArc 2.6.16.