Viewport normal drawing with constant length

Patch for: T37878

{F10169694}

Reviewed By: fclem

Differential Revision: https://developer.blender.org/D11487

release/datafiles/blender_icons.svg

@@ -17301,6 +17301,11 @@
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          inkscape:connector-curvature="0" />
     </g>
+    <path
+      style="color:#000000;font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;font-size:medium;line-height:normal;font-family:sans-serif;font-variant-ligatures:normal;font-variant-position:normal;font-variant-caps:normal;font-variant-numeric:normal;font-variant-alternates:normal;font-feature-settings:normal;text-indent:0;text-align:start;text-decoration:none;text-decoration-line:none;text-decoration-style:solid;text-decoration-color:#000000;letter-spacing:normal;word-spacing:normal;text-transform:none;writing-mode:lr-tb;direction:ltr;text-orientation:mixed;dominant-baseline:auto;baseline-shift:baseline;text-anchor:start;white-space:normal;shape-padding:0;clip-rule:nonzero;display:inline;overflow:visible;visibility:visible;opacity:0.98999999;isolation:auto;mix-blend-mode:normal;color-interpolation:sRGB;color-interpolation-filters:linearRGB;solid-color:#000000;solid-opacity:1;vector-effect:none;fill:#ffffff;fill-opacity:1;fill-rule:nonzero;stroke:none;stroke-width:1;stroke-linecap:round;stroke-linejoin:miter;stroke-miterlimit:4;stroke-dasharray:none;stroke-dashoffset:0;stroke-opacity:1;color-rendering:auto;image-rendering:auto;shape-rendering:auto;text-rendering:auto;enable-background:new"
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+      id="path3261"
+      inkscape:connector-curvature="0" />
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      inkscape:groupmode="layer"

release/scripts/startup/bl_ui/space_view3d.py

@@ -6386,7 +6386,13 @@ class VIEW3D_PT_overlay_edit_mesh_normals(Panel):
 
         sub = row.row(align=True)
         sub.active = overlay.show_vertex_normals or overlay.show_face_normals or overlay.show_split_normals
-        sub.prop(overlay, "normals_length", text="Size")
+        if overlay.use_normals_constant_screen_size:
+            sub.prop(overlay, "normals_constant_screen_size", text="Size")
+        else:
+            sub.prop(overlay, "normals_length", text="Size")
+
+        row.prop(overlay, "use_normals_constant_screen_size", text="", icon='FIXED_SIZE')
+
 
 
 class VIEW3D_PT_overlay_edit_mesh_freestyle(Panel):

source/blender/blenloader/intern/versioning_300.c

@@ -708,5 +708,19 @@ void blo_do_versions_300(FileData *fd, Library *UNUSED(lib), Main *bmain)
    */
   {
     /* Keep this block, even when empty. */
+
+    if (!DNA_struct_elem_find(
+            fd->filesdna, "View3DOverlay", "float", "normals_constant_screen_size")) {
+      LISTBASE_FOREACH (bScreen *, screen, &bmain->screens) {
+        LISTBASE_FOREACH (ScrArea *, area, &screen->areabase) {
+          LISTBASE_FOREACH (SpaceLink *, sl, &area->spacedata) {
+            if (sl->spacetype == SPACE_VIEW3D) {
+              View3D *v3d = (View3D *)sl;
+              v3d->overlay.normals_constant_screen_size = 7.0f;
+            }
+          }
+        }
+      }
+    }
   }
 }

source/blender/blenloader/intern/versioning_defaults.c

@@ -190,6 +190,7 @@ static void blo_update_defaults_screen(bScreen *screen,
       }
       /* Disable Curve Normals. */
       v3d->overlay.edit_flag &= ~V3D_OVERLAY_EDIT_CU_NORMALS;
+      v3d->overlay.normals_constant_screen_size = 7.0f;
     }
     else if (area->spacetype == SPACE_CLIP) {
       SpaceClip *sclip = area->spacedata.first;

source/blender/draw/engines/overlay/overlay_edit_mesh.c

@@ -132,6 +132,11 @@ void OVERLAY_edit_mesh_cache_init(OVERLAY_Data *vedata)
     DRW_shgroup_uniform_float_copy(grp, "normalSize", v3d->overlay.normals_length);
     DRW_shgroup_uniform_float_copy(grp, "alpha", backwire_opacity);
     DRW_shgroup_uniform_texture_ref(grp, "depthTex", depth_tex);
+    DRW_shgroup_uniform_bool_copy(grp,
+                                  "isConstantScreenSizeNormals",
+                                  (flag & V3D_OVERLAY_EDIT_CONSTANT_SCREEN_SIZE_NORMALS) != 0);
+    DRW_shgroup_uniform_float_copy(
+        grp, "normalScreenSize", v3d->overlay.normals_constant_screen_size);
   }
   {
     /* Mesh Analysis Pass */

source/blender/draw/engines/overlay/shaders/edit_mesh_normal_vert.glsl

@@ -1,5 +1,7 @@
 
 uniform float normalSize;
+uniform float normalScreenSize;
+uniform bool isConstantScreenSizeNormals;
 uniform sampler2D depthTex;
 uniform float alpha = 1.0;
 
@@ -49,11 +51,25 @@ void main()
   }
 
   vec3 n = normalize(normal_object_to_world(nor));
-
   vec3 world_pos = point_object_to_world(pos);
 
   if (gl_VertexID == 0) {
-    world_pos += n * normalSize;
+    if (isConstantScreenSizeNormals) {
+      bool is_persp = (ProjectionMatrix[3][3] == 0.0);
+      if (is_persp)
+      {
+        float dist_fac = length(cameraPos - world_pos);
+        float cos_fac = dot(cameraForward, cameraVec(world_pos));
+        world_pos += n * normalScreenSize * dist_fac * cos_fac * pixelFac * sizePixel;
+      }
+      else {
+        float frustrum_fac = mul_project_m4_v3_zfac(n) * sizePixel;
+        world_pos += n * normalScreenSize * frustrum_fac;
+      }
+    }
+    else {
+      world_pos += n * normalSize;
+    }
   }
 
   gl_Position = point_world_to_ndc(world_pos);

source/blender/editors/datafiles/CMakeLists.txt

@@ -583,6 +583,7 @@ set(ICON_NAMES
   uv_facesel
   uv_islandsel
   uv_sync_select
+  fixed_size
   transform_origins
   gizmo
   orientation_cursor

source/blender/editors/include/UI_icons.h

@@ -715,7 +715,7 @@ DEF_ICON(UV_ISLANDSEL)
 DEF_ICON(UV_SYNC_SELECT)
 DEF_ICON_BLANK(240)
 DEF_ICON_BLANK(241)
-DEF_ICON_BLANK(242)
+DEF_ICON(FIXED_SIZE)
 DEF_ICON(TRANSFORM_ORIGINS)
 DEF_ICON(GIZMO)
 DEF_ICON(ORIENTATION_CURSOR)

source/blender/makesdna/DNA_view3d_defaults.h

@@ -71,6 +71,7 @@
     .gpencil_paper_opacity = 0.5f, \
     .gpencil_grid_opacity = 0.9f, \
     .gpencil_vertex_paint_opacity = 1.0f, \
+    .normals_constant_screen_size = 7.0f, \
   }
 
 #define _DNA_DEFAULT_View3DCursor \

source/blender/makesdna/DNA_view3d_types.h

@@ -204,6 +204,7 @@ typedef struct View3DOverlay {
   /** Edit mode settings. */
   int edit_flag;
   float normals_length;
+  float normals_constant_screen_size;
   float backwire_opacity;
 
   /** Paint mode settings. */
@@ -238,6 +239,8 @@ typedef struct View3DOverlay {
   float gpencil_vertex_paint_opacity;
   /** Handles display type for curves. */
   int handle_display;
+
+  char _pad[4];
 } View3DOverlay;
 
 /* View3DOverlay->handle_display */
@@ -551,6 +554,7 @@ enum {
   // V3D_OVERLAY_EDIT_CU_HANDLES = (1 << 20),
 
   V3D_OVERLAY_EDIT_CU_NORMALS = (1 << 21),
+  V3D_OVERLAY_EDIT_CONSTANT_SCREEN_SIZE_NORMALS = (1 << 22),
 };
 
 /** #View3DOverlay.paint_flag */

source/blender/makesdna/DNA_view3d_types.h.rej

@@ -0,0 +1,9 @@
+diff a/source/blender/makesdna/DNA_view3d_types.h b/source/blender/makesdna/DNA_view3d_types.h	(rejected hunks)
+@@ -550,6 +553,7 @@
+   /* V3D_OVERLAY_EDIT_CU_HANDLES = (1 << 20),  */
+ 
+   V3D_OVERLAY_EDIT_CU_NORMALS = (1 << 21),
++  V3D_OVERLAY_EDIT_CONSTANT_SCREEN_SIZE_NORMALS = (1 << 22),
+ };
+ 
+ /** #View3DOverlay.paint_flag */

source/blender/makesrna/intern/rna_space.c

@@ -4363,6 +4363,21 @@ static void rna_def_space_view3d_overlay(BlenderRNA *brna)
   RNA_def_property_float_default(prop, 0.02);
   RNA_def_property_update(prop, NC_SPACE | ND_SPACE_VIEW3D, NULL);
 
+  prop = RNA_def_property(srna, "normals_constant_screen_size", PROP_FLOAT, PROP_PIXEL);
+  RNA_def_property_float_sdna(prop, NULL, "overlay.normals_constant_screen_size");
+  RNA_def_property_ui_text(prop, "Normal Screen Size", "Screen size for normals in the 3D view");
+  RNA_def_property_range(prop, 0.0, 100000.0);
+  RNA_def_property_ui_range(prop, 1.0, 100.0, 50, 0);
+  RNA_def_property_update(prop, NC_SPACE | ND_SPACE_VIEW3D, NULL);
+
+  prop = RNA_def_property(srna, "use_normals_constant_screen_size", PROP_BOOLEAN, PROP_NONE);
+  RNA_def_property_boolean_sdna(
+      prop, NULL, "overlay.edit_flag", V3D_OVERLAY_EDIT_CONSTANT_SCREEN_SIZE_NORMALS);
+  RNA_def_property_ui_text(prop,
+                           "Constant Screen Size Normals",
+                           "Keep size of normals constant in relation to 3D view");
+  RNA_def_property_update(prop, NC_SPACE | ND_SPACE_VIEW3D, NULL);
+
   prop = RNA_def_property(srna, "backwire_opacity", PROP_FLOAT, PROP_FACTOR);
   RNA_def_property_float_sdna(prop, NULL, "overlay.backwire_opacity");
   RNA_def_property_ui_text(prop, "Backwire Opacity", "Opacity when rendering transparent wires");