Modal operator help needed

Coding Python Support
1

Hi, I’d like to have this modal operation work for scrolling between vertex group index while weight painting.

import bpy
from bpy.props import IntProperty, FloatProperty


class ModalOperator(bpy.types.Operator):
    """Move an object with the mouse, example"""
    bl_idname = "object.modal_operator"
    bl_label = "Simple Modal Operator"

    first_mouse_x = IntProperty()
    first_value = FloatProperty()

    def modal(self, context, event):
        if event.type == 'MOUSEMOVE':
            if self.lmb:
                delta = self.first_mouse_x - event.mouse_x
                context.object.location.x = self.first_value + delta * 0.01

        elif event.type == 'LEFTMOUSE':
            # we could handle PRESS and RELEASE individually if necessary
            self.lmb = event.value == 'PRESS'

        elif event.type in {'RIGHTMOUSE', 'ESC'}:
            context.object.location.x = self.first_value
            return {'CANCELLED'}

        return {'RUNNING_MODAL'}

    def invoke(self, context, event):
        # variable to remember left mouse button state    
        self.lmb = False

        if context.object:
            self.first_mouse_x = event.mouse_x
            self.first_value = context.object.location.x

            context.window_manager.modal_handler_add(self)
            return {'RUNNING_MODAL'}
        else:
            self.report({'WARNING'}, "No active object, could not finish")
            return {'CANCELLED'}


def register():
    bpy.utils.register_class(ModalOperator)


def unregister():
    bpy.utils.unregister_class(ModalOperator)


if __name__ == "__main__":
    register()

    # test call
    bpy.ops.object.modal_operator('INVOKE_DEFAULT')

Thanks.

2

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3

Any python genius out there that can make this possible?

4

Okay, I got scrolling through vertex group index using mouse movement to work, the only problem is, how do I get weight painting to work during the modal operation?

Here is the solution, only need to have weight painting work while vgroup index changes
Just add 5 vertex groups and run script, search up “Start vGroup scrolling” to run operation
Press ESC key when done:

import bpy
from bpy.props import IntProperty, FloatProperty



class ModalOperator(bpy.types.Operator):
    """description"""
    bl_idname = "object.modal_operator"
    bl_label = "Start vGroup scrolling"

    first_mouse_x = IntProperty()
    first_value = FloatProperty()
    
    
    def modal(self, context, event):
        
        if event.type == 'MOUSEMOVE':
            if self.lmb:
            
                return {'PASS_THROUGH'}
        ob = bpy.context.active_object
        delta = self.first_mouse_x - event.mouse_x
      
        index=  delta *0.01 %  5
        
        if event.type == 'LEFTMOUSE':

            if event.value == 'PRESS':
                mesh = bpy.context.object

                mesh.vertex_groups.active_index = index
           
                
                return {'PASS_THROUGH'}
            
            if event.value == 'RELEASE':
                return {'PASS_THROUGH'}
        
        
        if event.type == 'MOUSEMOVE':
            mesh = bpy.context.object

            mesh.vertex_groups.active_index = index
           
   
                
            return {'PASS_THROUGH'}
           
        elif event.type in {'RIGHTMOUSE', 'ESC'}:
            context.area.header_text_set
            
            return {'CANCELLED'}
 
        
        
                    
        return {'PASS_THROUGH'}
        
        
 
    def invoke(self, context, event):
        self.lmb= False
        
           
        if context.object:
            

            self.first_mouse_x = event.mouse_x
            
            
            
            context.window_manager.modal_handler_add(self)
            return {'RUNNING_MODAL'}
        else:
            self.report({'WARNING'}, "No active object, could not finish")
            return {'CANCELLED'}


def register():
    bpy.utils.register_class(ModalOperator)


def unregister():
    bpy.utils.unregister_class(ModalOperator)


if __name__ == "__main__":
    register()

    # test call
    #bpy.ops.object.modal_operator('INVOKE_DEFAULT')

hopefully I receive a solution to this.