# ##### BEGIN GPL LICENSE BLOCK ##### # # slope.py , a Blender addon # (c) 2013,2024 Michel J. Anders (varkenvarken) # # This program is free software; you can redistribute it and/or # modify it under the terms of the GNU General Public License # as published by the Free Software Foundation; either version 2 # of the License, or (at your option) any later version. # # This program is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU General Public License for more details. # # You should have received a copy of the GNU General Public License # along with this program; if not, write to the Free Software Foundation, # Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. # # ##### END GPL LICENSE BLOCK ##### bl_info = { "name": "Slope", "author": "Michel Anders (varkenvarken)", "version": (0, 0, 20240408080000), "blender": (4, 1, 0), "location": "View3D > Weights > Slope and View3D > Paint > Slope", "description": "Replace active vertex group or vertex color layer with values representing the slope of a face", "warning": "", "wiki_url": "", "tracker_url": "", "category": "Mesh", } from math import pi, pow from re import search import bpy from mathutils import Vector class Slope: def weight(self, normal, reference=Vector((0, 0, 1))): angle = normal.angle(reference) if self.mirror and angle > pi / 2: angle = pi - angle weight = 0.0 if angle <= self.low: weight = 1.0 elif angle <= self.high: weight = 1 - (angle - self.low) / (self.high - self.low) weight = pow(weight, self.power) return weight class Slope2VGroup(bpy.types.Operator, Slope): bl_idname = "mesh.slope2vgroup" bl_label = "Slope2VGroup" bl_options = {"REGISTER", "UNDO"} low: bpy.props.FloatProperty( name="Lower limit", description="Angles smaller than this get a unit weight", subtype="ANGLE", default=0, max=pi, min=0, ) high: bpy.props.FloatProperty( name="Upper limit", description="Angles larger than this get a zero weight", subtype="ANGLE", default=pi / 2, max=pi, min=0.01, ) power: bpy.props.FloatProperty( name="Power", description="Shape of mapping curve", default=1, min=0, max=10 ) mirror: bpy.props.BoolProperty( name="Mirror", description="Limit angle to 90 degrees", default=False ) worldspace: bpy.props.BoolProperty( name="World space", description="Use world space instead of object space coordinates", default=False, ) @classmethod def poll(self, context): p = ( context.mode == "PAINT_WEIGHT" and isinstance(context.active_object, bpy.types.Object) and isinstance(context.active_object.data, bpy.types.Mesh) ) return p def execute(self, context): bpy.ops.object.mode_set(mode="OBJECT") ob = context.active_object wmat = ob.matrix_world vertex_group = ob.vertex_groups.active if vertex_group is None: bpy.ops.object.vertex_group_add() vertex_group = ob.vertex_groups.active mesh = ob.data reference = Vector((0, 0, 1)) if self.worldspace: reference = reference @ wmat for v in mesh.vertices: vertex_group.add([v.index], self.weight(v.normal, reference), "REPLACE") bpy.ops.object.mode_set(mode="WEIGHT_PAINT") bpy.ops.object.mode_set(mode="EDIT") bpy.ops.object.mode_set(mode="WEIGHT_PAINT") context.view_layer.update() return {"FINISHED"} class Slope2VCol(bpy.types.Operator, Slope): bl_idname = "mesh.slope2vcol" bl_label = "Slope2Vcol" bl_options = {"REGISTER", "UNDO"} low: bpy.props.FloatProperty( name="Lower limit", description="Angles smaller than this get a unit weight", subtype="ANGLE", default=0, max=pi, min=0, ) high: bpy.props.FloatProperty( name="Upper limit", description="Angles larger than this get a zero weight", subtype="ANGLE", default=pi / 2, max=pi, min=0.01, ) power: bpy.props.FloatProperty( name="Power", description="Shape of mapping curve", default=1, min=0, max=10 ) mirror: bpy.props.BoolProperty( name="Mirror", description="Limit angle to 90 degrees", default=False ) curve: bpy.props.BoolProperty( name="Use brush curve", description="Apply brush curve after calculculating values", default=False, ) normal: bpy.props.BoolProperty( name="Map normal", description="Convert face normal to vertex colors instead of slope angle", default=False, ) worldspace: bpy.props.BoolProperty( name="World space", description="Use world space instead of object space coordinates", default=False, ) @classmethod def poll(self, context): p = ( context.mode == "PAINT_VERTEX" and isinstance(context.active_object, bpy.types.Object) and isinstance(context.active_object.data, bpy.types.Mesh) ) return p def execute(self, context): if self.curve: bcurvemap = context.tool_settings.vertex_paint.brush.curve bcurvemap.initialize() bcurve = bcurvemap.curves[0] wmat = context.active_object.matrix_world mesh = context.active_object.data vertex_colors = mesh.vertex_colors.active.data for poly in mesh.polygons: for loop_index in range(poly.loop_start, poly.loop_start + poly.loop_total): pnormal = poly.normal if self.normal: if self.worldspace: pnormal = wmat @ pnormal pnormal = pnormal.normalized() vertex_colors[loop_index].color = [ (pnormal.x + 1) / 2, (pnormal.y + 1) / 2, (pnormal.z + 1) / 2, 1, ] else: if self.worldspace: weight = self.weight(pnormal, Vector((0, 0, 1)) @ wmat) else: weight = self.weight(pnormal) if self.curve: weight = bcurvemap.evaluate(bcurve, 1.0 - weight) vertex_colors[loop_index].color = [weight, weight, weight, 1.0] bpy.ops.object.mode_set(mode="VERTEX_PAINT") bpy.ops.object.mode_set(mode="EDIT") bpy.ops.object.mode_set(mode="VERTEX_PAINT") context.view_layer.update() return {"FINISHED"} def draw( self, context ): # provide a draw function here to show use brush option only with versions that have the new initialize function layout = self.layout if not self.curve and not self.normal: layout.prop(self, "low") layout.prop(self, "high") layout.prop(self, "power") if not self.curve: layout.prop(self, "normal") if not self.normal: layout.prop(self, "mirror") if not self.normal: layout.prop(self, "curve") if self.curve: layout.label( text="Run Paint -> Slope again\n after changing brush curve!" ) def menu_func_weight(self, context): self.layout.operator(Slope2VGroup.bl_idname, text="Slope", icon="PLUGIN") def menu_func_vcol(self, context): self.layout.operator(Slope2VCol.bl_idname, text="Slope", icon="PLUGIN") def register(): bpy.utils.register_class(Slope2VCol) bpy.utils.register_class(Slope2VGroup) bpy.types.VIEW3D_MT_paint_weight.append(menu_func_weight) bpy.types.VIEW3D_MT_paint_vertex.append(menu_func_vcol) def unregister(): bpy.types.VIEW3D_MT_paint_weight.remove(menu_func_weight) bpy.types.VIEW3D_MT_paint_vertex.remove(menu_func_vcol) bpy.utils.unregister_class(Slope2VCol) bpy.utils.unregister_class(Slope2VGroup)