Cycles: change Index output of Hair and Particle Info to Random, in 0..1 range.

These are used for randomization, so it's convenient if the index is already
hashed and consistent with the Object Info node.

1 files changed, 6 insertions, 14 deletions

diff --git a/intern/cycles/blender/blender_curves.cpp b/intern/cycles/blender/blender_curves.cpp
index c8eb879e5cb..f7cb0b66d29 100644
--- a/intern/cycles/blender/blender_curves.cpp
+++ b/intern/cycles/blender/blender_curves.cpp
@@ -25,6 +25,7 @@
 #include "blender/blender_util.h"
 
 #include "util/util_foreach.h"
+#include "util/util_hash.h"
 #include "util/util_logging.h"
 
 CCL_NAMESPACE_BEGIN
@@ -565,12 +566,12 @@ static void ExportCurveSegments(Scene *scene, Mesh *mesh, ParticleCurveData *CDa
 		return;
 
 	Attribute *attr_intercept = NULL;
-	Attribute *attr_index = NULL;
+	Attribute *attr_random = NULL;
 
 	if(mesh->need_attribute(scene, ATTR_STD_CURVE_INTERCEPT))
 		attr_intercept = mesh->curve_attributes.add(ATTR_STD_CURVE_INTERCEPT);
-	if(mesh->need_attribute(scene, ATTR_STD_CURVE_INDEX))
-		attr_index = mesh->curve_attributes.add(ATTR_STD_CURVE_INDEX);
+	if(mesh->need_attribute(scene, ATTR_STD_CURVE_RANDOM))
+		attr_random = mesh->curve_attributes.add(ATTR_STD_CURVE_RANDOM);
 
 	/* compute and reserve size of arrays */
 	for(int sys = 0; sys < CData->psys_firstcurve.size(); sys++) {
@@ -615,8 +616,8 @@ static void ExportCurveSegments(Scene *scene, Mesh *mesh, ParticleCurveData *CDa
 				num_curve_keys++;
 			}
 
-			if(attr_index != NULL) {
-				attr_index->add(num_curves);
+			if(attr_random != NULL) {
+				attr_random->add(hash_int_01(num_curves));
 			}
 
 			mesh->add_curve(num_keys, CData->psys_shader[sys]);
@@ -625,15 +626,6 @@ static void ExportCurveSegments(Scene *scene, Mesh *mesh, ParticleCurveData *CDa
 		}
 	}
 
-	if(attr_index != NULL) {
-		/* Normalize index to 0..1 range. */
-		float *curve_index = attr_index->data_float();
-		const float norm_factor = 1.0f / (float)num_curves;
-		for(int i = 0; i < num_curves; ++i) {
-			curve_index[i] *= norm_factor;
-		}
-	}
-
 	/* check allocation */
 	if((mesh->curve_keys.size() != num_keys) || (mesh->num_curves() != num_curves)) {
 		VLOG(1) << "Allocation failed, clearing data";