[Bf-blender-cvs] [3232d8ec8f1] master: Fix T51951: cell noise texture precision issue at unit vertex coordinates.

[Brecht Van Lommel]

Commit: 3232d8ec8f15ad00ff16fd4326258de0b0b83486
Author: Brecht Van Lommel
Date:   Sun Jul 2 21:53:23 2017 +0200
Branches: master
https://developer.blender.org/rB3232d8ec8f15ad00ff16fd4326258de0b0b83486

Fix T51951: cell noise texture precision issue at unit vertex coordinates.

Solution is to bias the coordinates a little, same as Cycles checker texture.

===================================================================

M	source/blender/blenlib/intern/noise.c

===================================================================

diff --git a/source/blender/blenlib/intern/noise.c b/source/blender/blenlib/intern/noise.c
index f834c5b4c74..347640aae0d 100644
--- a/source/blender/blenlib/intern/noise.c
+++ b/source/blender/blenlib/intern/noise.c
@@ -1394,6 +1394,11 @@ static float voronoi_CrS(float x, float y, float z)
 /* returns unsigned cellnoise */
 static float cellNoiseU(float x, float y, float z)
 {
+	/* avoid precision issues on unit coordinates */
+	x = (x + 0.000001f)*0.999999f;
+	y = (y + 0.000001f)*0.999999f;
+	z = (z + 0.000001f)*0.999999f;
+
 	int xi = (int)(floor(x));
 	int yi = (int)(floor(y));
 	int zi = (int)(floor(z));
@@ -1411,6 +1416,11 @@ float cellNoise(float x, float y, float z)
 /* returns a vector/point/color in ca, using point hasharray directly */
 void cellNoiseV(float x, float y, float z, float ca[3])
 {
+	/* avoid precision issues on unit coordinates */
+	x = (x + 0.000001f)*0.999999f;
+	y = (y + 0.000001f)*0.999999f;
+	z = (z + 0.000001f)*0.999999f;
+
 	int xi = (int)(floor(x));
 	int yi = (int)(floor(y));
 	int zi = (int)(floor(z));