Is it me or BMRT who is inconsistent?

Is it me or BMRT who is inconsistent?

Post by Ture P?lsso » Wed, 12 Aug 1998 04:00:00



(I tried to send this as a private mail to Larry Gritz but apparently,
someone at Pixar has decided that the entire Link?ping University is a
spam originating site, and I have to work around that somehow).

When rendering foo.rib from the enclosed tar file with BMRT 2.3.6b on
Solaris 2.6, P.z inside the volume shader is 6 and I.z = 6, which
seems consistent with the (visibility) ray entering the volume at P-I
and leaving it at P.

However, when rendering bar.rib, P.z is still 6, while I.z is
"infinity". Since the ray enters the volume at the polygon (z = 6) and
never leaves it, I was expecting P.z = "very large" and P.z - I.z = 6.
Am I missing something here?


begin 664 example.tar.gz

MX6V_9?L^`/>XPWWF^A2`44Z="=!1_U6O*G6D`":Z4N*G>?O.'ZD;J;)(UU><


MWNK//W7K7^=+X[<OW]&+I?S]_',ZY)]Y7IM_9F/^#V&4_%_H3);%LU#B:P7`
MP/]!336VRG34-?;E'SPVY-^A?IM_FV'^#Z'LM^7F.9B:QKO1W(^K!,Y!JWI\


2A!!"""&$$!K!)SA%=TH`*```
`
end

 
 
 

Is it me or BMRT who is inconsistent?

Post by Ture P?lsso » Wed, 12 Aug 1998 04:00:00


[ nice explanation of the values of P and I inside volume shaders ]

Many thanks for the explanation. Now I understand why I couldn't get
consistent results between BMRT and my own raytracer... :-)

  -- Ture