Fix T77681, T92634: noise texture artifacts with high detail

We run into float precision issues here, clamp the number of octaves to
one less, which has little to no visual difference. This was empirically
determined to work up to 16 before, but with additional inputs like
roughness only 15 appears to work.

Also adds misisng clamp for the geometry nodes implementation.

2 files changed, 24 insertions, 24 deletions

diff --git a/source/blender/gpu/shaders/material/gpu_shader_material_fractal_noise.glsl b/source/blender/gpu/shaders/material/gpu_shader_material_fractal_noise.glsl
index f25691c1a83..95f2be4bd44 100644
--- a/source/blender/gpu/shaders/material/gpu_shader_material_fractal_noise.glsl
+++ b/source/blender/gpu/shaders/material/gpu_shader_material_fractal_noise.glsl
@@ -5,7 +5,7 @@ float fractal_noise(float p, float octaves, float roughness)
   float amp = 1.0;
   float maxamp = 0.0;
   float sum = 0.0;
-  octaves = clamp(octaves, 0.0, 16.0);
+  octaves = clamp(octaves, 0.0, 15.0);
   int n = int(octaves);
   for (int i = 0; i <= n; i++) {
     float t = noise(fscale * p);
@@ -34,7 +34,7 @@ float fractal_noise(vec2 p, float octaves, float roughness)
   float amp = 1.0;
   float maxamp = 0.0;
   float sum = 0.0;
-  octaves = clamp(octaves, 0.0, 16.0);
+  octaves = clamp(octaves, 0.0, 15.0);
   int n = int(octaves);
   for (int i = 0; i <= n; i++) {
     float t = noise(fscale * p);
@@ -63,7 +63,7 @@ float fractal_noise(vec3 p, float octaves, float roughness)
   float amp = 1.0;
   float maxamp = 0.0;
   float sum = 0.0;
-  octaves = clamp(octaves, 0.0, 16.0);
+  octaves = clamp(octaves, 0.0, 15.0);
   int n = int(octaves);
   for (int i = 0; i <= n; i++) {
     float t = noise(fscale * p);
@@ -92,7 +92,7 @@ float fractal_noise(vec4 p, float octaves, float roughness)
   float amp = 1.0;
   float maxamp = 0.0;
   float sum = 0.0;
-  octaves = clamp(octaves, 0.0, 16.0);
+  octaves = clamp(octaves, 0.0, 15.0);
   int n = int(octaves);
   for (int i = 0; i <= n; i++) {
     float t = noise(fscale * p);
diff --git a/source/blender/gpu/shaders/material/gpu_shader_material_tex_musgrave.glsl b/source/blender/gpu/shaders/material/gpu_shader_material_tex_musgrave.glsl
index 7ecca286acd..586385b7e86 100644
--- a/source/blender/gpu/shaders/material/gpu_shader_material_tex_musgrave.glsl
+++ b/source/blender/gpu/shaders/material/gpu_shader_material_tex_musgrave.glsl
@@ -19,7 +19,7 @@ void node_tex_musgrave_fBm_1d(vec3 co,
 {
   float p = w * scale;
   float H = max(dimension, 1e-5);
-  float octaves = clamp(detail, 0.0, 16.0);
+  float octaves = clamp(detail, 0.0, 15.0);
   float lacunarity = max(lac, 1e-5);
 
   float value = 0.0;
@@ -59,7 +59,7 @@ void node_tex_musgrave_multi_fractal_1d(vec3 co,
 {
   float p = w * scale;
   float H = max(dimension, 1e-5);
-  float octaves = clamp(detail, 0.0, 16.0);
+  float octaves = clamp(detail, 0.0, 15.0);
   float lacunarity = max(lac, 1e-5);
 
   float value = 1.0;
@@ -100,7 +100,7 @@ void node_tex_musgrave_hetero_terrain_1d(vec3 co,
 {
   float p = w * scale;
   float H = max(dimension, 1e-5);
-  float octaves = clamp(detail, 0.0, 16.0);
+  float octaves = clamp(detail, 0.0, 15.0);
   float lacunarity = max(lac, 1e-5);
 
   float pwHL = pow(lacunarity, -H);
@@ -146,7 +146,7 @@ void node_tex_musgrave_hybrid_multi_fractal_1d(vec3 co,
 {
   float p = w * scale;
   float H = max(dimension, 1e-5);
-  float octaves = clamp(detail, 0.0, 16.0);
+  float octaves = clamp(detail, 0.0, 15.0);
   float lacunarity = max(lac, 1e-5);
 
   float pwHL = pow(lacunarity, -H);
@@ -196,7 +196,7 @@ void node_tex_musgrave_ridged_multi_fractal_1d(vec3 co,
 {
   float p = w * scale;
   float H = max(dimension, 1e-5);
-  float octaves = clamp(detail, 0.0, 16.0);
+  float octaves = clamp(detail, 0.0, 15.0);
   float lacunarity = max(lac, 1e-5);
 
   float pwHL = pow(lacunarity, -H);
@@ -241,7 +241,7 @@ void node_tex_musgrave_fBm_2d(vec3 co,
 {
   vec2 p = co.xy * scale;
   float H = max(dimension, 1e-5);
-  float octaves = clamp(detail, 0.0, 16.0);
+  float octaves = clamp(detail, 0.0, 15.0);
   float lacunarity = max(lac, 1e-5);
 
   float value = 0.0;
@@ -281,7 +281,7 @@ void node_tex_musgrave_multi_fractal_2d(vec3 co,
 {
   vec2 p = co.xy * scale;
   float H = max(dimension, 1e-5);
-  float octaves = clamp(detail, 0.0, 16.0);
+  float octaves = clamp(detail, 0.0, 15.0);
   float lacunarity = max(lac, 1e-5);
 
   float value = 1.0;
@@ -322,7 +322,7 @@ void node_tex_musgrave_hetero_terrain_2d(vec3 co,
 {
   vec2 p = co.xy * scale;
   float H = max(dimension, 1e-5);
-  float octaves = clamp(detail, 0.0, 16.0);
+  float octaves = clamp(detail, 0.0, 15.0);
   float lacunarity = max(lac, 1e-5);
 
   float pwHL = pow(lacunarity, -H);
@@ -368,7 +368,7 @@ void node_tex_musgrave_hybrid_multi_fractal_2d(vec3 co,
 {
   vec2 p = co.xy * scale;
   float H = max(dimension, 1e-5);
-  float octaves = clamp(detail, 0.0, 16.0);
+  float octaves = clamp(detail, 0.0, 15.0);
   float lacunarity = max(lac, 1e-5);
 
   float pwHL = pow(lacunarity, -H);
@@ -418,7 +418,7 @@ void node_tex_musgrave_ridged_multi_fractal_2d(vec3 co,
 {
   vec2 p = co.xy * scale;
   float H = max(dimension, 1e-5);
-  float octaves = clamp(detail, 0.0, 16.0);
+  float octaves = clamp(detail, 0.0, 15.0);
   float lacunarity = max(lac, 1e-5);
 
   float pwHL = pow(lacunarity, -H);
@@ -463,7 +463,7 @@ void node_tex_musgrave_fBm_3d(vec3 co,
 {
   vec3 p = co * scale;
   float H = max(dimension, 1e-5);
-  float octaves = clamp(detail, 0.0, 16.0);
+  float octaves = clamp(detail, 0.0, 15.0);
   float lacunarity = max(lac, 1e-5);
 
   float value = 0.0;
@@ -503,7 +503,7 @@ void node_tex_musgrave_multi_fractal_3d(vec3 co,
 {
   vec3 p = co * scale;
   float H = max(dimension, 1e-5);
-  float octaves = clamp(detail, 0.0, 16.0);
+  float octaves = clamp(detail, 0.0, 15.0);
   float lacunarity = max(lac, 1e-5);
 
   float value = 1.0;
@@ -544,7 +544,7 @@ void node_tex_musgrave_hetero_terrain_3d(vec3 co,
 {
   vec3 p = co * scale;
   float H = max(dimension, 1e-5);
-  float octaves = clamp(detail, 0.0, 16.0);
+  float octaves = clamp(detail, 0.0, 15.0);
   float lacunarity = max(lac, 1e-5);
 
   float pwHL = pow(lacunarity, -H);
@@ -590,7 +590,7 @@ void node_tex_musgrave_hybrid_multi_fractal_3d(vec3 co,
 {
   vec3 p = co * scale;
   float H = max(dimension, 1e-5);
-  float octaves = clamp(detail, 0.0, 16.0);
+  float octaves = clamp(detail, 0.0, 15.0);
   float lacunarity = max(lac, 1e-5);
 
   float pwHL = pow(lacunarity, -H);
@@ -640,7 +640,7 @@ void node_tex_musgrave_ridged_multi_fractal_3d(vec3 co,
 {
   vec3 p = co * scale;
   float H = max(dimension, 1e-5);
-  float octaves = clamp(detail, 0.0, 16.0);
+  float octaves = clamp(detail, 0.0, 15.0);
   float lacunarity = max(lac, 1e-5);
 
   float pwHL = pow(lacunarity, -H);
@@ -685,7 +685,7 @@ void node_tex_musgrave_fBm_4d(vec3 co,
 {
   vec4 p = vec4(co, w) * scale;
   float H = max(dimension, 1e-5);
-  float octaves = clamp(detail, 0.0, 16.0);
+  float octaves = clamp(detail, 0.0, 15.0);
   float lacunarity = max(lac, 1e-5);
 
   float value = 0.0;
@@ -725,7 +725,7 @@ void node_tex_musgrave_multi_fractal_4d(vec3 co,
 {
   vec4 p = vec4(co, w) * scale;
   float H = max(dimension, 1e-5);
-  float octaves = clamp(detail, 0.0, 16.0);
+  float octaves = clamp(detail, 0.0, 15.0);
   float lacunarity = max(lac, 1e-5);
 
   float value = 1.0;
@@ -766,7 +766,7 @@ void node_tex_musgrave_hetero_terrain_4d(vec3 co,
 {
   vec4 p = vec4(co, w) * scale;
   float H = max(dimension, 1e-5);
-  float octaves = clamp(detail, 0.0, 16.0);
+  float octaves = clamp(detail, 0.0, 15.0);
   float lacunarity = max(lac, 1e-5);
 
   float pwHL = pow(lacunarity, -H);
@@ -812,7 +812,7 @@ void node_tex_musgrave_hybrid_multi_fractal_4d(vec3 co,
 {
   vec4 p = vec4(co, w) * scale;
   float H = max(dimension, 1e-5);
-  float octaves = clamp(detail, 0.0, 16.0);
+  float octaves = clamp(detail, 0.0, 15.0);
   float lacunarity = max(lac, 1e-5);
 
   float pwHL = pow(lacunarity, -H);
@@ -862,7 +862,7 @@ void node_tex_musgrave_ridged_multi_fractal_4d(vec3 co,
 {
   vec4 p = vec4(co, w) * scale;
   float H = max(dimension, 1e-5);
-  float octaves = clamp(detail, 0.0, 16.0);
+  float octaves = clamp(detail, 0.0, 15.0);
   float lacunarity = max(lac, 1e-5);
 
   float pwHL = pow(lacunarity, -H);