BSLIVE 0008 / Blender Automation for USDZ

[enzyme69]

TASK: Without opening Blender (running Blender in the background via Command Line and Python) create a setup that allows user to provide CUSTOM TEXT that will generate 3D mesh and output OBJ and USDZ for Augmented Reality (AR Quick Look, iOS 12, on iPhone or iPad).

PROCEDURES:

• User needs to provide TEXT from external Blender, save text
• Run simple command line to run Blender in the background, update text from outside (resolve conflict) using provided Python code (see below)
• Inside the BLEND itself I already have Animation Nodes setup to automatically update the text, so not everything is using Python and BPY
• Generate and export OBJ of every mesh in Blender as a single OBJ output
• Convert OBJ into USDZ, with USDA as intermediate object (for material etc)

blender_auto_usdz.zip

[enzyme69]

Actual intermediate BLEND file is like this:

It has Animation Nodes ready to update the 3D Text based on the external TEXT we supply.

[enzyme69]

This is Python code that is running when Blender is summoned on the command line: blender -b mytext.blend -P BSexport.py

# BSexport.py
# SOURCE https://blenderartists.org/t/synchronizing-text-with-changes-from-outside/499187/5

import bpy
import os

def updateExternalTexts():
    """ Check modified external scripts in the scene and update if possible
    """
    ctx = bpy.context.copy()
    #Ensure  context area is not None

    ctx['area'] = ctx['screen'].areas[0]

    for t in bpy.data.texts:
        if t.is_modified and not t.is_in_memory:
            print("  *** Warning: Updating external script ***", t.name)
            # Change current context to contain a TEXT_EDITOR
            oldAreaType = ctx['area'].type
            ctx['area'].type = 'TEXT_EDITOR'
            ctx['edit_text'] = t

            bpy.ops.text.resolve_conflict(ctx, resolution='RELOAD')
            #print("---------everything works!")

            #Restore context
            ctx['area'].type = oldAreaType    

def exportOBJ():

    blend_file_path = bpy.data.filepath
    directory = os.path.dirname(blend_file_path)
    target_file = os.path.join(directory, 'mytext.obj')

    bpy.ops.export_scene.obj(filepath=target_file)

def convertUSDZ():
    os.system("xcrun usdz_converter mytext.obj mytext.usdz -v -a -l")

print("....updating text")            
updateExternalTexts()

print("....exporting OBJ")            
exportOBJ()

print("....converting OBJ to USDZ")            
convertUSDZ()