Gpencil Noise - Add noise offset parameter

This patch adds a noise offset option to the grease pencil noise modifier.
It allows the user to animate the noise along the length of the stroke to create movement that is currently not possible.

It works by adding an offset to the noise table and adding the remaining floating point value to the noise table sampling.

Reviewed By: #grease_pencil

Differential Revision: https://developer.blender.org/D10021

2 files changed, 3 insertions, 0 deletions

diff --git a/source/blender/makesdna/DNA_gpencil_modifier_defaults.h b/source/blender/makesdna/DNA_gpencil_modifier_defaults.h
index fdb77bfd196..399bf6f0a6d 100644
--- a/source/blender/makesdna/DNA_gpencil_modifier_defaults.h
+++ b/source/blender/makesdna/DNA_gpencil_modifier_defaults.h
@@ -152,6 +152,7 @@
     .factor_thickness = 0.0f, \
     .factor_uvs = 0.0f, \
     .noise_scale = 0.0f, \
+    .noise_offset = 0.0f, \
     .step = 4, \
     .layer_pass = 0, \
     .seed = 1, \
diff --git a/source/blender/makesdna/DNA_gpencil_modifier_types.h b/source/blender/makesdna/DNA_gpencil_modifier_types.h
index 9ac40495887..1f7283a1c70 100644
--- a/source/blender/makesdna/DNA_gpencil_modifier_types.h
+++ b/source/blender/makesdna/DNA_gpencil_modifier_types.h
@@ -107,6 +107,8 @@ typedef struct NoiseGpencilModifierData {
   float factor_uvs;
   /** Noise Frequency scaling */
   float noise_scale;
+  float noise_offset;
+  char _pad[4];
   /** How many frames before recalculate randoms. */
   int step;
   /** Custom index for passes. */