Feature request: Dyntopo detail expressed in percentage of brush radius.

Not sure how useful this will be but people have requested it so, here
it is...

4 files changed, 23 insertions, 4 deletions

diff --git a/release/scripts/startup/bl_ui/space_view3d_toolbar.py b/release/scripts/startup/bl_ui/space_view3d_toolbar.py
index 51dd8b05f93..5fa3a559ab9 100644
--- a/release/scripts/startup/bl_ui/space_view3d_toolbar.py
+++ b/release/scripts/startup/bl_ui/space_view3d_toolbar.py
@@ -1471,6 +1471,8 @@ class VIEW3D_PT_sculpt_dyntopo(Panel, View3DPaintPanel):
             row = sub.row(align=True)
             row.prop(sculpt, "constant_detail")
             row.operator("sculpt.sample_detail_size", text="", icon='EYEDROPPER')
+        elif (sculpt.detail_type_method == 'BRUSH'):
+            sub.prop(sculpt, "detail_percent")
         else:
             sub.prop(sculpt, "detail_size")
         sub.prop(sculpt, "detail_refine_method", text="")
diff --git a/source/blender/editors/sculpt_paint/sculpt.c b/source/blender/editors/sculpt_paint/sculpt.c
index 1d2f623bf9d..e2403a57556 100644
--- a/source/blender/editors/sculpt_paint/sculpt.c
+++ b/source/blender/editors/sculpt_paint/sculpt.c
@@ -4379,6 +4379,9 @@ static void sculpt_stroke_update_step(bContext *C, struct PaintStroke *UNUSED(st
 	if (sd->flags & SCULPT_DYNTOPO_DETAIL_CONSTANT) {
 		BKE_pbvh_bmesh_detail_size_set(ss->pbvh, sd->constant_detail / 100.0f);
 	}
+	else if (sd->flags & SCULPT_DYNTOPO_DETAIL_BRUSH) {
+		BKE_pbvh_bmesh_detail_size_set(ss->pbvh, ss->cache->radius * sd->detail_percent / 100.0f);
+	}
 	else {
 		BKE_pbvh_bmesh_detail_size_set(
 		        ss->pbvh,
@@ -5072,10 +5075,10 @@ static int sculpt_mode_toggle_exec(bContext *C, wmOperator *op)
 			ts->sculpt->flags |= SCULPT_DYNTOPO_SUBDIVIDE | SCULPT_DYNTOPO_COLLAPSE;
 		}
 
-		if (!ts->sculpt->detail_size) {
+		if (!ts->sculpt->detail_size)
 			ts->sculpt->detail_size = 12;
-		}
-
+		if (!ts->sculpt->detail_percent)
+			ts->sculpt->detail_percent = 25;
 		if (ts->sculpt->constant_detail == 0.0f)
 			ts->sculpt->constant_detail = 30.0f;
 
@@ -5308,6 +5311,10 @@ static int sculpt_set_detail_size_exec(bContext *C, wmOperator *UNUSED(op))
 		set_brush_rc_props(&props_ptr, "sculpt", "constant_detail", NULL, 0);
 		RNA_string_set(&props_ptr, "data_path_primary", "tool_settings.sculpt.constant_detail");
 	}
+	else if (sd->flags & SCULPT_DYNTOPO_DETAIL_BRUSH) {
+		set_brush_rc_props(&props_ptr, "sculpt", "constant_detail", NULL, 0);
+		RNA_string_set(&props_ptr, "data_path_primary", "tool_settings.sculpt.detail_percent");
+	}
 	else {
 		set_brush_rc_props(&props_ptr, "sculpt", "detail_size", NULL, 0);
 		RNA_string_set(&props_ptr, "data_path_primary", "tool_settings.sculpt.detail_size");
diff --git a/source/blender/makesdna/DNA_scene_types.h b/source/blender/makesdna/DNA_scene_types.h
index ff2a7468832..a40b8aff08e 100644
--- a/source/blender/makesdna/DNA_scene_types.h
+++ b/source/blender/makesdna/DNA_scene_types.h
@@ -1021,6 +1021,8 @@ typedef struct Sculpt {
 
 	/* scale for constant detail size */
 	float constant_detail;
+	float detail_percent;
+	float pad;
 
 	struct Object *gravity_object;
 	void *pad2;
@@ -1851,7 +1853,8 @@ typedef enum SculptFlags {
 	SCULPT_DYNTOPO_COLLAPSE = (1 << 11),
 
 	/* If set, dynamic-topology detail size will be constant in object space */
-	SCULPT_DYNTOPO_DETAIL_CONSTANT = (1 << 13)
+	SCULPT_DYNTOPO_DETAIL_CONSTANT = (1 << 13),
+	SCULPT_DYNTOPO_DETAIL_BRUSH = (1 << 14),
 } SculptFlags;
 
 typedef enum ImagePaintMode {
diff --git a/source/blender/makesrna/intern/rna_sculpt_paint.c b/source/blender/makesrna/intern/rna_sculpt_paint.c
index a975ea3d7e4..d5e99d4f3e9 100644
--- a/source/blender/makesrna/intern/rna_sculpt_paint.c
+++ b/source/blender/makesrna/intern/rna_sculpt_paint.c
@@ -462,6 +462,8 @@ static void rna_def_sculpt(BlenderRNA  *brna)
 		 "Relative Detail", "Mesh detail is relative to the brush size and detail size"},
 		{SCULPT_DYNTOPO_DETAIL_CONSTANT, "CONSTANT", 0,
 		 "Constant Detail", "Mesh detail is constant in object space according to detail size"},
+	    {SCULPT_DYNTOPO_DETAIL_BRUSH, "BRUSH", 0,
+		 "Brush Detail", "Mesh detail is relative to brush radius"},
 		{0, NULL, 0, NULL, NULL}
 	};
 
@@ -519,6 +521,11 @@ static void rna_def_sculpt(BlenderRNA  *brna)
 	RNA_def_property_ui_text(prop, "Detail Size", "Maximum edge length for dynamic topology sculpting (in pixels)");
 	RNA_def_property_update(prop, NC_SCENE | ND_TOOLSETTINGS, NULL);
 
+	prop = RNA_def_property(srna, "detail_percent", PROP_FLOAT, PROP_PERCENTAGE);
+	RNA_def_property_ui_range(prop, 0.5, 100.0, 10, 2);
+	RNA_def_property_ui_text(prop, "Detail Percentage", "Maximum edge length for dynamic topology sculpting (in brush percenage)");
+	RNA_def_property_update(prop, NC_SCENE | ND_TOOLSETTINGS, NULL);
+
 	prop = RNA_def_property(srna, "constant_detail", PROP_FLOAT, PROP_PERCENTAGE);
 	RNA_def_property_range(prop, 0.001, 10000.0);
 	RNA_def_property_ui_range(prop, 0.1, 100.0, 10, 2);