Create custom object class without accessing bpy.ops

Question

I want to spawn my own custom primitive objects (in this case a sphere from an underlying cube mesh) and store it as an object in a variable.

I have managed to write a class that creates such objects, but I want to be able to store them inside a variable and then manipulate them using the class's methods. If you're wondering what the end goal is: I want to create a model of the solar system and this class is meant to create planets and stars.

My current code looks like this

import bpy
import time
import numpy

start = time.time()

# Reset scene after each execution
bpy.ops.object.select_all(action='SELECT')
bpy.ops.object.delete(use_global=False, confirm=False)

# Been told this has less wrinkles in the mesh around the poles.
# Hopefully this will make UV unwrapping and texturing easier down the line.

class cube_sphere():
    # r is radius of the sphere
    # R is the distance from the origin (location of the sun)
    def __init__(self,r,R):
        self.r = r
        self.R = R
        # adds the cube and fashions it into a sphere 
        bpy.ops.mesh.primitive_uv_sphere_add(radius=self.r, enter_editmode=False, align='WORLD', location=(0, self.R, 0), scale=(1, 1, 1)) 
        bpy.ops.object.subdivision_set(level=3, relative=False)
        bpy.context.object.modifiers["Subdivision"].levels = 3
        bpy.context.object.modifiers["Subdivision"].render_levels = 3
        bpy.ops.object.modifier_apply(modifier="Subdivision")
        bpy.ops.object.editmode_toggle()
        bpy.ops.transform.tosphere(value=1, mirror=True, use_proportional_edit=False, proportional_edit_falloff='SMOOTH', proportional_size=1, use_proportional_connected=False, use_proportional_projected=False)
        bpy.ops.object.editmode_toggle()
        bpy.ops.object.shade_smooth()


# idk what is being put into variable a, but I'm almost certain it is not an object that inherits from the class that actually defines primitive meshes in blender.
a = cube_sphere(1,0)

end = time.time()
print(end-start)

I've been told that using bpy.ops is very slow since it always comes with a scene update. This is why I time the execution to see how quickly everything is running.

What I'd like to know is how I can store the actual cube object in a variable and then manipulate it by referencing the variable I stored it in. (not actual code)

a = bpy.objects.cube()
a.set_edgelength(2)
a.rotate(0,0,1)

Or in the case of my custom class:

class(bpy.objects.cube):

    def __init__(self,r,R):
        super().__init__() # I think that's how you do it if you specify a parent class in class(parent_class)?
        self.r = r
        self.R = R

    def set_something(self,something):
        self.something = something
        ...

Can this be done and where can I read up on that sort of stuff?

Answer 1

import bpy
from math import pi 


C = bpy.context

bpy.ops.mesh.primitive_cube_add()

#the most recent object added to the scene is the active object. You can assign active object to a variable
cube = C.active_object
#another way to assign object to variable is by its name
cube = C.scene.objects["Cube"]
#another way to assign object to variable is by its index (camera is index 0, light is index 1 of collection)
cube = C.scene.objects[2]



initialFrame = 1
#here I play with some functions that can be performed on the object variable
#set objects values at an initial frame
cube.location = (0, 0, 0)
cube.scale = (1, 1, 1)
cube.rotation_euler = (0, 0, 0)

#keyframe the initial values
cube.keyframe_insert("location", frame= initialFrame)
cube.keyframe_insert("scale", frame = initialFrame)
cube.keyframe_insert("rotation_euler", frame= initialFrame)


finalFrame = 60

#set objects values at an final frame
cube.location = (0, 0, 1)
cube.scale = (2, 2, 2)
cube.rotation_euler = (0, 0, pi/2)

#keyframe the final values
cube.keyframe_insert("location", frame= finalFrame)
cube.keyframe_insert("scale", frame = finalFrame)
cube.keyframe_insert("rotation_euler", frame= finalFrame)

Towards the top of this script I wrote above, I assigned a cube object to a variable in three different ways. I also showed how some of the cubes properties can be changed with the built in functions location, scale, and rotation_euler. I think a.rotation_euler should take care of your desire for something such as "a.rotate(0,0,1)" For "a.set_edgelength" I can't find a built in function that can achieve a specific change in edgelength. I would hope that a.scale does the trick. If not, there are ways to change the objects individual vertices.