[tuhopuu-devel] [ tuhopuu-Feature Requests-188 ] Minimally invasive Selective Raytracing

[tuhopuu-devel@blender.org]

Feature Requests item #188, was opened at 2003-04-20 10:44
You can respond by visiting: 
http://projects.blender.org/tracker/?func=detail&atid=136&aid=188&group_id=11

Category: None
Group: None
Status: Open
Priority: 5
Submitted By: Robert Wenzlaff (rwenzlaff)
Assigned to: Nobody (None)
Summary: Minimally invasive Selective Raytracing

Initial Comment:
We came up with an idea on how to impliment selective 
raytracing with very little change to Blender's internal structure.  
It uses an external raytracer and the texture plug-in interface to 
communicate the raytrace contribution to blender.  
 
General method (this was an on the fly rant I came up with 
#blenderchat) 
  
1) start of frame, export scene to raytracer which buffers it. 
(Either by script or through the RIB interface). 
 
2) on the raytracer side all materials have diffuse reflection set 
to 0 
 
3) when texture is called it passes the screen coord to the 
raytracer that calcs that (sub) pixel only 
 
4) since the raytrace difuse reflections are 0, the result is simply 
added to Blenders internal calculation (that is all difuse 
reflections) and passed back to the render. 
 
5) Ideally, setting for thing that Blender does not handle (IOR, 
Caustics, etc) wolu be handled as inputs to the texture plug-in, 
but that would need to be passed at the begining of the frame to 
the raytracer as scene data.  So that might be another minor 
change to Blender needed, so the export can access those 
sliders (though it might now, I don't know). 
 
It might need minor changes to the Blender plug-in system to 
take into account sub-pixel stuff.   But no major overhaul of 
Blender. 
 
Which is what adding a raytracer directly to Blender might need. 
 
Butt we'd need to select an OS raytracer that could be modified 
with the buffer and wait for a pixel command thing,  so we don't 
have to reload scene data every for pixel that need raytracing. 
--  
************************************************************ 
If the source code is of any help to a cracker in decrypting 
 a data stream, then the binary wasn't particularly helpful 
           to the user when encrypting it. 
************************************************************ 
Robert Wenzlaff                  rwenzlaff@soylent-green.com 

----------------------------------------------------------------------

You can respond by visiting: 
http://projects.blender.org/tracker/?func=detail&atid=136&aid=188&group_id=11