Anvil Blender Uplink connection

Anvil Q&A
#1

Hi Guys,

I’m trying out anvil as a possible way of building some pipeline tools for Blender.

I successfully got uplink to work, I can call a function inside blender from the web interface, and get a message back.

But when I try to call some native blender code, I get some errors.

If I call the same code in the blender console, it works without any issues.

Code Sample:

import anvil.server

import bpy

import threading

anvil.server.connect("my uplink key")

def to_run(): # should not take arguments.
    ... # code to execute in the thread (can be a loop, ...) 
        # it uses the same variables as in the main thread.
    anvil.server.wait_forever()

new_thread = threading.Thread() # create a new thread object.
new_thread.run = to_run
new_thread.start() # the new thread is created and then is running.


def selected_objects():
    return bpy.context.selected_objects


@anvil.server.callable
def get_selected_objects():
    
    selected_objects_names = []
    objects = selected_objects()
    
    for ob in objects:
        selected_objects_names.append(ob.name)
    
    
    return selected_objects_names ```

This is the error I am getting inside anvil:

AttributeError: 'Context' object has no attribute 'selected_objects'
at /Anvil.py, line 24
  called from Form1, line 14

The anvil app is a simple textbox and button, and it’s supposed to show the list of selected objects from blender, in the text box when pressing the button.

#2

include @anvil.server.callable above

def selected_objects():

and try?

#3

Doesn’t work, I also tried including all code in 1 function. Some other people mentioned it might be because the new thread doesn’t have access to the same variables as the main thread.

#4

You may be inadvertently running your callables from another module.

Check all your environments for the setting enviornment - show advanced settings - uplink keys - send server calls from other environments to this uplink.

Make sure you are running the uplink version 0.3.42 or above.

#5

Hmm, as far as I understand this would be the case if having multiple environments.

I’m on the free tier, so only have 1 environment.

It works partially, because if I call a function in blender that returns a string, I can display it my anvil app, but I cannot call internal blender functions from the browser.

That’s why I’m leaning to believe it is a problem about how I am setting up the threads inside blender, and not a problem about anvil itself.

#6

is it possible if you could set up a virtual-env in blender and then try to run the code in that new virtual-env?

i’m guessing you installed anvil uplink in a virtual-env and run the code there. however when u run from the console the code is running in root-env ?

#7

From what I understand blender is running it’s own python interpreter, and it’s not possible to set-up a virtual environment. But I’m not an experienced developer so can’t say for sure.

#8

Ok, I have found a solution, it seems that for some reason bpy.context doesn’t work remotely. But bpy.data gives me access to all the scene data directly, and I can get access to everything.

But I just realised a problem.

I am using a @anvil.server.callable function. I want to be able to give this script to multiple people, to let the control blender from their browser.

Is there any way to let each user call their own @anvil.server.callable function? From their instance of blender? Or is there any other better way to do this?

EDIT:

Nevermind, I have found this other thread that provides a solution by using custom function names based on the ID:

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