LineArt: Camera Overscan

Expand camera effective region to a portion beyond image frame so strokes won't end right at the border.

Reviewed By: Antonio Vazquez (antoniov)

Differential Revision: https://developer.blender.org/D12049

2 files changed, 8 insertions, 1 deletions

diff --git a/source/blender/makesdna/DNA_gpencil_modifier_defaults.h b/source/blender/makesdna/DNA_gpencil_modifier_defaults.h
index b9697beeea9..81e9abc4916 100644
--- a/source/blender/makesdna/DNA_gpencil_modifier_defaults.h
+++ b/source/blender/makesdna/DNA_gpencil_modifier_defaults.h
@@ -307,6 +307,7 @@
     .calculation_flags = LRT_ALLOW_DUPLI_OBJECTS | LRT_ALLOW_CLIPPING_BOUNDARIES, \
     .angle_splitting_threshold = DEG2RAD(60.0f), \
     .chaining_image_threshold = 0.001f, \
+    .overscan = 0.1f,\
   }
 
 #define _DNA_DEFAULT_LengthGpencilModifierData \
diff --git a/source/blender/makesdna/DNA_gpencil_modifier_types.h b/source/blender/makesdna/DNA_gpencil_modifier_types.h
index fac5bd3d4f4..6ffaf457d63 100644
--- a/source/blender/makesdna/DNA_gpencil_modifier_types.h
+++ b/source/blender/makesdna/DNA_gpencil_modifier_types.h
@@ -963,6 +963,12 @@ typedef struct LineartGpencilModifierData {
   char source_vertex_group[64];
   char vgname[64];
 
+  /* Camera focal length is divided by (1 + overscan), before caluclation, which give a wider FOV,
+   * this doesn't change coordinates range internally (-1, 1), but makes the caluclated frame
+   * bigger than actual output. This is for the easier shifting calculation. A value of 0.5 means
+   * the "internal" focal length become 2/3 of the actual camera. */
+  float overscan;
+
   float opacity;
   short thickness;
 
@@ -970,7 +976,7 @@ typedef struct LineartGpencilModifierData {
   unsigned char material_mask_bits;
   unsigned char intersection_mask;
 
-  char _pad[7];
+  char _pad[3];
 
   /** `0..1` range for cosine angle */
   float crease_threshold;