add explode model

- Add method that allows for exploding the model into pieces for kit bashing or painting in substance painter.

functions/tools/general_mesh_tools.py

@@ -1,7 +1,7 @@
 import bpy
 import numpy as np
 from bpy.types import Operator, Context
-from typing import Set
+from typing import Set, Literal
 from ...core.translations import t
 from ...core.logging_setup import logger
 from ...core.common import get_active_armature, get_all_meshes
@@ -99,3 +99,96 @@ class AvatarToolkit_OT_SelectShortestSeamPath(Operator):
     
         return {'FINISHED'}
 
+class AvatarToolkit_OT_ExplodeMesh(Operator):
+    """Explodes the mesh for use with painting programs, or painting inside blender."""
+    bl_idname = "avatar_toolkit.explode_mesh"
+    bl_label = t("Tools.explode_mesh")
+    bl_description = t("Tools.explode_mesh_desc")
+    bl_options = {'REGISTER', 'UNDO'}
+    distance: bpy.props.FloatProperty(default=2.0,name=t("Tools.explode_mesh.distance"),description=t("Tools.explode_mesh.distance_desc"))
+    split_on_seams: bpy.props.BoolProperty(default=True,name=t("Tools.explode_mesh.split_on_seams"),description=t("Tools.explode_mesh.split_on_seams_desc"))
+
+    def draw(self, context: Context) -> None:
+        """Draw the operator's UI"""
+        layout = self.layout
+        layout.prop(self, "distance")
+
+    def invoke(self, context: Context, event: bpy.types.Event) -> set[str]:
+        """Initialize the operator"""
+        return context.window_manager.invoke_props_dialog(self)
+    
+    @classmethod
+    def poll(cls, context: Context) -> bool:
+
+        return context.view_layer.objects.active.type == "MESH" and len(context.view_layer.objects.selected) == 1
+    
+    
+
+    def execute(self, context: Context) -> Set[str]:
+
+        mesh_obj: bpy.types.Object = context.view_layer.objects.active.type
+        mesh: bpy.types.Mesh = context.view_layer.objects.active.data
+        if(self.split_on_seams):
+            
+            #set to correct mode
+            bpy.ops.object.mode_set(mode='EDIT')
+            bpy.ops.mesh.select_mode(type='EDGE')
+
+            #mark seams by islands
+            bpy.ops.mesh.select_all(action="SELECT")
+            bpy.ops.uv.select_all(action="SELECT")
+            bpy.ops.uv.seams_from_islands(mark_seams=True,mark_sharp=False)
+            
+            #clear selection
+            bpy.ops.mesh.select_all(action="DESELECT")
+            bpy.ops.object.mode_set(mode='OBJECT')
+            bm = bmesh.new()   # create an empty BMesh
+            bm.from_mesh(mesh)   # fill it in from active mesh
+
+            #select seam edges
+            for idx,edge in enumerate(bm.edges):
+                edge.select = edge.seam
+            bm.to_mesh(mesh)
+            bm.free()
+
+            #split edges.
+            bpy.ops.object.mode_set(mode='EDIT')
+            bpy.ops.mesh.edge_split()
+        
+        #separate by loose.
+        bpy.ops.object.mode_set(mode='EDIT')
+        bpy.ops.mesh.select_mode(type='FACE')
+        
+        bpy.ops.mesh.select_all(action="SELECT")
+        
+        bpy.ops.mesh.separate(type='LOOSE')
+
+        
+        distance: float = self.distance
+        
+
+        #set origins to geometry
+        bpy.ops.object.mode_set(mode='OBJECT')
+        bpy.ops.object.origin_set(type="ORIGIN_GEOMETRY",center="BOUNDS")
+
+        #store original settings
+        origin_only_orig: bool = context.scene.tool_settings.use_transform_data_origin
+        pos_only_orig: bool = context.scene.tool_settings.use_transform_pivot_point_align
+        parents_only_orig: bool = context.scene.tool_settings.use_transform_skip_children
+        original_pivot: Literal['BOUNDING_BOX_CENTER', 'CURSOR', 'INDIVIDUAL_ORIGINS', 'MEDIAN_POINT', 'ACTIVE_ELEMENT'] = context.scene.tool_settings.transform_pivot_point 
+
+        #set scene settings correctly.
+        context.scene.tool_settings.use_transform_data_origin = False
+        context.scene.tool_settings.use_transform_pivot_point_align = True
+        context.scene.tool_settings.use_transform_skip_children = False
+        context.scene.tool_settings.transform_pivot_point = 'MEDIAN_POINT'
+
+        #spread out separated objects
+        bpy.ops.transform.resize(value=(self.distance, self.distance, self.distance), orient_type='GLOBAL')
+        
+        #restore settings.
+        context.scene.tool_settings.use_transform_data_origin = origin_only_orig
+        context.scene.tool_settings.use_transform_pivot_point_align = pos_only_orig
+        context.scene.tool_settings.use_transform_skip_children = parents_only_orig
+        context.scene.tool_settings.transform_pivot_point = original_pivot
+        return {'FINISHED'}