110 lines
3.5 KiB
Python
110 lines
3.5 KiB
Python
import bpy
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from bpy_extras import view3d_utils
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def main(context, event):
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"""Run this function on left mouse, execute the ray cast"""
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# get the context arguments
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scene = context.scene
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region = context.region
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rv3d = context.region_data
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coord = event.mouse_region_x, event.mouse_region_y
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# get the ray from the viewport and mouse
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view_vector = view3d_utils.region_2d_to_vector_3d(region, rv3d, coord)
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ray_origin = view3d_utils.region_2d_to_origin_3d(region, rv3d, coord)
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ray_target = ray_origin + view_vector
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def visible_objects_and_duplis():
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"""Loop over (object, matrix) pairs (mesh only)"""
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for obj in context.visible_objects:
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if obj.type == 'MESH':
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yield (obj, obj.matrix_world.copy())
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if obj.instance_type != 'NONE':
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obj.dupli_list_create(scene)
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for dob in obj.dupli_list:
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obj_dupli = dob.object
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if obj_dupli.type == 'MESH':
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yield (obj_dupli, dob.matrix.copy())
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obj.dupli_list_clear()
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def obj_ray_cast(obj, matrix):
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"""Wrapper for ray casting that moves the ray into object space"""
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# get the ray relative to the object
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matrix_inv = matrix.inverted()
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ray_origin_obj = matrix_inv @ ray_origin
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ray_target_obj = matrix_inv @ ray_target
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ray_direction_obj = ray_target_obj - ray_origin_obj
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# cast the ray
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success, location, normal, face_index = obj.ray_cast(ray_origin_obj, ray_direction_obj)
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if success:
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return location, normal, face_index
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else:
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return None, None, None
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# cast rays and find the closest object
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best_length_squared = -1.0
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best_obj = None
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for obj, matrix in visible_objects_and_duplis():
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if obj.type == 'MESH':
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hit, normal, face_index = obj_ray_cast(obj, matrix)
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if hit is not None:
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hit_world = matrix @ hit
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scene.cursor_location = hit_world
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length_squared = (hit_world - ray_origin).length_squared
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if best_obj is None or length_squared < best_length_squared:
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best_length_squared = length_squared
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best_obj = obj
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# now we have the object under the mouse cursor,
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# we could do lots of stuff but for the example just select.
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if best_obj is not None:
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best_obj.select_set(True)
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context.view_layer.objects.active = best_obj
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class ViewOperatorRayCast(bpy.types.Operator):
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"""Modal object selection with a ray cast"""
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bl_idname = "view3d.modal_operator_raycast"
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bl_label = "RayCast View Operator"
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def modal(self, context, event):
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if event.type in {'MIDDLEMOUSE', 'WHEELUPMOUSE', 'WHEELDOWNMOUSE'}:
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# allow navigation
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return {'PASS_THROUGH'}
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elif event.type == 'LEFTMOUSE':
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main(context, event)
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return {'RUNNING_MODAL'}
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elif event.type in {'RIGHTMOUSE', 'ESC'}:
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return {'CANCELLED'}
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return {'RUNNING_MODAL'}
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def invoke(self, context, event):
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if context.space_data.type == 'VIEW_3D':
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context.window_manager.modal_handler_add(self)
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return {'RUNNING_MODAL'}
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else:
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self.report({'WARNING'}, "Active space must be a View3d")
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return {'CANCELLED'}
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def register():
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bpy.utils.register_class(ViewOperatorRayCast)
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def unregister():
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bpy.utils.unregister_class(ViewOperatorRayCast)
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if __name__ == "__main__":
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register()
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