[Bf-blender-cvs] SVN commit: /data/svn/bf-blender [58253] branches/soc-2013-dingto/intern/ cycles: Cycles / Blackbody node:

[Thomas Dinges]

Revision: 58253
          http://projects.blender.org/scm/viewvc.php?view=rev&root=bf-blender&revision=58253
Author:   dingto
Date:     2013-07-15 04:38:35 +0000 (Mon, 15 Jul 2013)
Log Message:
-----------
Cycles / Blackbody node:
* Fix the weird results with 800-804.3 Kelvin in SVM. This was an offset issue with the lookup table, made the table slightly larger now (from 954 to 956) which gives a small gap between the R/G/B components. 
* Use Luminance also for values below 800 Kelvin, for consistency.

Modified Paths:
--------------
    branches/soc-2013-dingto/intern/cycles/kernel/svm/svm_blackbody.h
    branches/soc-2013-dingto/intern/cycles/render/blackbody.cpp

Modified: branches/soc-2013-dingto/intern/cycles/kernel/svm/svm_blackbody.h
===================================================================
--- branches/soc-2013-dingto/intern/cycles/kernel/svm/svm_blackbody.h	2013-07-15 03:54:57 UTC (rev 58252)
+++ branches/soc-2013-dingto/intern/cycles/kernel/svm/svm_blackbody.h	2013-07-15 04:38:35 UTC (rev 58253)
@@ -47,9 +47,9 @@
 		color_rgb = make_float3(1.0e-6f,0.0f,0.0f);
 	}
 	else if (temperature <= BB_MAX_TABLE_RANGE) {
-		/* This is the overall size of the table (317*3+3) */
-		const int lookuptablesize = 954;
-		const float lookuptablesizef = 954.0f;
+		/* This is the overall size of the table */
+		const int lookuptablesize = 956;
+		const float lookuptablesizef = 956.0f;
 
 		/* reconstruct a proper index for the table lookup, compared to OSL we don't look up two colors
 		just one (the OSL-lerp is also automatically done for us by "lookup_table_read") */
@@ -60,21 +60,21 @@
 		/* Retrieve colors from the lookup table */
 		float lutval = t/lookuptablesizef;
 		float R = lookup_table_read(kg, lutval, blackbody_table_offset, lookuptablesize);
-		lutval = (t + 317.0f*1.0f)/lookuptablesizef;
+		lutval = (t + 319.0f*1.0f)/lookuptablesizef;
 		float G = lookup_table_read(kg, lutval, blackbody_table_offset, lookuptablesize);
-		lutval = (t + 317.0f*2.0f)/lookuptablesizef;
+		lutval = (t + 319.0f*2.0f)/lookuptablesizef;
 		float B = lookup_table_read(kg, lutval, blackbody_table_offset, lookuptablesize);
 
 		R = powf(R, BB_TABLE_YPOWER);
 		G = powf(G, BB_TABLE_YPOWER);
 		B = powf(B, BB_TABLE_YPOWER);
 
-		/* Luminance */
-		float l = linear_rgb_to_gray(make_float3(R, G, B));
-
 		color_rgb = make_float3(R, G, B);
-		color_rgb /= l;
 	}
+	
+	/* Luminance */
+	float l = linear_rgb_to_gray(color_rgb);
+	color_rgb /= l;
 
 	if (stack_valid(col_offset))
 		stack_store_float3(stack, col_offset, color_rgb);

Modified: branches/soc-2013-dingto/intern/cycles/render/blackbody.cpp
===================================================================
--- branches/soc-2013-dingto/intern/cycles/render/blackbody.cpp	2013-07-15 03:54:57 UTC (rev 58252)
+++ branches/soc-2013-dingto/intern/cycles/render/blackbody.cpp	2013-07-15 04:38:35 UTC (rev 58253)
@@ -93,8 +93,8 @@
 								   // h is Planck's const, k is Boltzmann's
 	const float dlambda = 5.0f * 1e-9;  // in meters
 
-	/* Blackbody table from 800 to 12k Kelvin (317 entries) */
-	vector<float> blackbody_table(317*3+3);
+	/* Blackbody table from 800 to 12k Kelvin (319 entries (317+2 offset) * 3) */
+	vector<float> blackbody_table(956);
 
 	float X, Y, Z;
 
@@ -131,8 +131,8 @@
 
 		/* Store in table in RRRGGGBBB format */
 		blackbody_table[i] = col.x;
-		blackbody_table[i+317*1] = col.y;
-		blackbody_table[i+317*2] = col.z;	
+		blackbody_table[i+319*1] = col.y;
+		blackbody_table[i+319*2] = col.z;	
 	}
 
 	return blackbody_table;