--- ray/doc/ray.html 2003/04/07 15:43:08 1.2 +++ ray/doc/ray.html 2010/03/12 18:43:30 1.9 @@ -1,22 +1,20 @@ -The RADIANCE 3.5 Synthetic Imaging System +The RADIANCE 4.0 Synthetic Imaging System -Copyright © 2003 Regents, University of California -

-The RADIANCE 3.5 Synthetic Imaging System +The RADIANCE 4.0 Synthetic Imaging System

-Building Technologies Department
+Building Technologies Program
Lawrence Berkeley National Laboratory
1 Cyclotron Rd., 90-3111
Berkeley, CA 94720
@@ -566,7 +564,7 @@ A material defines the way light interacts with a sur

- Mirror is used for planar surfaces that produce secondary source reflections. + Mirror is used for planar surfaces that produce virtual source reflections. This material should be used sparingly, as it may cause the light source calculation to blow up if it is applied to many small surfaces. This material is only supported for flat surfaces such as polygons and rings. The arguments are simply the RGB reflectance values, which should be between 0 and 1. @@ -589,12 +587,12 @@ This is only appropriate if the surface hides other (m
- The prism1 material is for general light redirection from prismatic glazings, generating secondary light sources. + The prism1 material is for general light redirection from prismatic glazings, generating virtual light sources. It can only be used to modify a planar surface (i.e., a polygon or disk) and should not result in either light concentration or scattering. The new direction of the ray can be on either side of the material, - and the definitions must have the correct bidirectional properties to work properly with secondary light sources. + and the definitions must have the correct bidirectional properties to work properly with virtual light sources. The arguments give the coefficient for the redirected light and its direction. 
@@ -661,7 +659,7 @@ a perfectly scattering medium (no absorption).
 The scattering eccentricity parameter will likewise override the global
 setting if it is present.
 Scattering eccentricity indicates how much scattered light favors the
-forward direction, as fit by the Heyney-Greenstein function:
+forward direction, as fit by the Henyey-Greenstein function:
 
 
 	P(theta) = (1 - g*g) / (1 + g*g - 2*g*cos(theta))^1.5
@@ -1367,8 +1365,6 @@ A mixfunc mixes  two  modifiers  procedurally.   It  i
 	which serves as a form of opacity control when used with a material.)
 	Vname is the coefficient defined in funcfile that determines  the  influence  of  foreground.   
 	The background coefficient is always (1-vname).  
-	Since the references are not resolved until run-time,  the  last  definitions  of  the modifier id's will be used.  
-	This can result in modifier loops, which are detected by the renderer.
 
 

 
@@ -1530,10 +1526,8 @@ If no file is needed by a given primitive because all
 the  required  variables  are global,  
 a  period  (`.')  can be given in place of the file name.  
 It is also possible to give an expression instead
-of a  straight  variable  name  in  a scene file, 
-although such expressions should be kept
-simple if possible.
-Also, functions (requiring parameters) must be given
+of a  straight  variable  name  in  a scene file.
+Functions (requiring parameters) must be given
 as names and not as expressions.
 
 

@@ -1680,8 +1674,8 @@ The details of this process  are  not  important, but 
 directs the use of a scene description.