New user with change for Object_Print3D_Utils

I was working with Blender on a large scale project and was using the Print3D add-on to obtain area and volume.
But Print3D ignores scene scale and returns everything in centimeters, not meters, which is a real pain, especially with the lack of commas to break up the dozen significant figures.

So I figured out some code to look it up and be more flexible. If it is METRIC and isn’t set to METERS then it defaults back to using centimeters.

But I’m an old, self-taught coder who isn’t current and I’d rather not screw things up.

Can someone who knows the process please review my code below for operators.py in '\scripts\addons\object_print3d_utils" ? New lines (7) are commented accordingly, and comma and indent for else block added to 2 original lines.

# ---------
# Mesh Info

class MESH_OT_print3d_info_volume(Operator):
    bl_idname = "mesh.print3d_info_volume"
    bl_label = "3D-Print Info Volume"
    bl_description = "Report the volume of the active mesh"

def execute(self, context):
    scene = context.scene
    unit = scene.unit_settings
    scale = 1.0 if unit.system == 'NONE' else unit.scale_length
    length = "cm" if unit.system == 'NONE' else unit.length_unit #adds variable to check unit length in use
    obj = context.active_object

    bm = mesh_helpers.bmesh_copy_from_object(obj, apply_modifiers=True)
    volume = bm.calc_volume()
    bm.free()

    if unit.system == 'METRIC':
        volume_cm = volume * (scale ** 3.0) / (0.01 ** 3.0)
        volume_metres = volume_cm/1000000
        volume_fmt = f"{length}"
        if length == "METERS":    #uses new variable to apply correct format
                volume_fmt = "{} m".format(clean_float(f"{volume_metres:,.2f}"))
        else:                       #on else default to the original code, but with commas too
                volume_fmt = "{} cm".format(clean_float(f"{volume_cm:,.4f}"))
    elif unit.system == 'IMPERIAL':
        volume_inch = volume * (scale ** 3.0) / (0.0254 ** 3.0)
        volume_fmt = '{} "'.format(clean_float(f"{volume_inch:.4f}"))
    else:
        volume_fmt = clean_float(f"{volume:.8f}")

    report.update((f"Volume: {volume_fmt}³", None))

    return {'FINISHED'}


class MESH_OT_print3d_info_area(Operator):
    bl_idname = "mesh.print3d_info_area"
    bl_label = "3D-Print Info Area"
    bl_description = "Report the surface area of the active mesh"

def execute(self, context):
    scene = context.scene
    unit = scene.unit_settings
    scale = 1.0 if unit.system == 'NONE' else unit.scale_length
    length = "cm" if unit.system == 'NONE' else unit.length_unit #adds variable to check unit length in use
    obj = context.active_object

    bm = mesh_helpers.bmesh_copy_from_object(obj, apply_modifiers=True)
    area = mesh_helpers.bmesh_calc_area(bm)
    bm.free()

    if unit.system == 'METRIC':
        area_cm = area * (scale ** 2.0) / (0.01 ** 2.0)
        area_metres = area_cm /10000
        if length == "METERS":        #uses new variable to apply correct format**
                area_fmt = "{} m".format(clean_float(f"{area_metres:,.2f}"))**
        else:                           #on else default to the original code, but with commas too
                area_fmt = "{} cm".format(clean_float(f"{area_cm:,.4f}"))
    elif unit.system == 'IMPERIAL':
        area_inch = area * (scale ** 2.0) / (0.0254 ** 2.0)
        area_fmt = '{} "'.format(clean_float(f"{area_inch:.4f}"))
    else:
        area_fmt = clean_float(f"{area:.8f}")

    report.update((f"Area: {area_fmt}²", None))

    return {'FINISHED'}

Please submit any code contributions here:
https://developer.blender.org/differential/diff/create/

That’s my point.
It is a one-off change that I thought would be useful for people, without going through a whole developer process I don’t know.
And your suggestion is to sign up for something else and go through some other process…

Hi, I am the current maintainer for 3D Print add-on. Your solution is not acceptable in it’s current form, as it is too limited:

  • It does not account for millimeter scale.
  • What if user wants to have scene in one scale, but get volume/area in different scale?

That is why patch review process is important.

An adequate solution would be add-on preference or operator option (or both).
I will get around to implement that some time later.