Function from Python not being loaded for Driver when project opened #61063

New Issue

stephen thomas · 2019-01-31T15:36:25+01:00

stephen thomas commented

2019-01-31 15:36:25 +01:00

System Information
Operating system: Pop!_OS (Debian) 18.10
Graphics card: GTX Titan X

Blender Version
Broken:
2.80 77eaa4790d
Worked: (optional)

A driver calls on a python function. The python function is internal and registered.

When the project is opened, the driver can't find the function, throwing up "ERROR: Invalid Python expression".

Pressing "Update Dependencies" fixes the problem

Exact steps for others to reproduce the error
With 'driver-bug-test.blend':

Open the project.
Enter pose mode for the armature
Try moving it along the X axis (Moving the armature along the x axis should make the cube move along the Y-axis, but it doesn't)
Exit pose mode
Select the cube
In the Drivers panel, you'll see in the Driver Property panel an error "ERROR: Invalid Python expression"
Clicking 'Update Dependencies' allows the driver to start working correctly.

This happens each time the project is opened.

I'd be happy to just click this button each time I load, but if you have a project with many items being driven by functions, it's not practical at all.

driver-bug-test.blend

**System Information** Operating system: Pop!_OS (Debian) 18.10 Graphics card: GTX Titan X **Blender Version** Broken: 2.80 77eaa4790d37 Worked: (optional) A driver calls on a python function. The python function is internal and registered. When the project is opened, the driver can't find the function, throwing up "ERROR: Invalid Python expression". Pressing "Update Dependencies" fixes the problem **Exact steps for others to reproduce the error** With 'driver-bug-test.blend': - Open the project. - Enter pose mode for the armature - Try moving it along the X axis (Moving the armature along the x axis should make the cube move along the Y-axis, but it doesn't) - Exit pose mode - Select the cube - In the Drivers panel, you'll see in the Driver Property panel an error "ERROR: Invalid Python expression" - Clicking 'Update Dependencies' allows the driver to start working correctly. This happens each time the project is opened. I'd be happy to just click this button each time I load, but if you have a project with many items being driven by functions, it's not practical at all. [driver-bug-test.blend](https://archive.blender.org/developer/F6465381/driver-bug-test.blend)

stephen thomas commented

2019-01-31 15:36:25 +01:00

Added subscriber: @stephenthomas

Brecht Van Lommel commented

2019-01-31 18:34:29 +01:00

Added subscribers: @Sergey, @brecht

Brecht Van Lommel commented

2019-01-31 18:34:29 +01:00

@Sergey, this traces back to d192d723.

Python module registration should be done before the depsgraph like in 2.7 I think, for cases like this. Wouldn't mind an extra pair of eyes to check if it's safe though.

diff --git a/source/blender/windowmanager/intern/wm_files.c b/source/blender/windowmanager/intern/wm_files.c
index 120bf65..5295064 100644
--- a/source/blender/windowmanager/intern/wm_files.c
+++ b/source/blender/windowmanager/intern/wm_files.c
@@ -491,12 +491,6 @@ static void wm_file_read_post(
 
        CTX_wm_window_set(C, wm->windows.first);
 
-       Main *bmain = CTX_data_main(C);
-       DEG_on_visible_update(bmain, true);
-       wm_event_do_depsgraph(C);
-
-       ED_editors_init(C);
-
 #ifdef WITH_PYTHON
        if (is_startup_file) {
                /* possible python hasn't been initialized */
@@ -526,6 +520,12 @@ static void wm_file_read_post(
        UNUSED_VARS(is_startup_file, reset_app_template);
 #endif  /* WITH_PYTHON */
 
+       Main *bmain = CTX_data_main(C);
+       DEG_on_visible_update(bmain, true);
+       wm_event_do_depsgraph(C);
+
+       ED_editors_init(C);
+
        WM_operatortype_last_properties_clear_all();
 
        /* important to do before NULL'ing the context */

@Sergey, this traces back to d192d723. Python module registration should be done before the depsgraph like in 2.7 I think, for cases like this. Wouldn't mind an extra pair of eyes to check if it's safe though. ``` diff --git a/source/blender/windowmanager/intern/wm_files.c b/source/blender/windowmanager/intern/wm_files.c index 120bf65..5295064 100644 --- a/source/blender/windowmanager/intern/wm_files.c +++ b/source/blender/windowmanager/intern/wm_files.c @@ -491,12 +491,6 @@ static void wm_file_read_post( CTX_wm_window_set(C, wm->windows.first); - Main *bmain = CTX_data_main(C); - DEG_on_visible_update(bmain, true); - wm_event_do_depsgraph(C); - - ED_editors_init(C); - #ifdef WITH_PYTHON if (is_startup_file) { /* possible python hasn't been initialized */ @@ -526,6 +520,12 @@ static void wm_file_read_post( UNUSED_VARS(is_startup_file, reset_app_template); #endif /* WITH_PYTHON */ + Main *bmain = CTX_data_main(C); + DEG_on_visible_update(bmain, true); + wm_event_do_depsgraph(C); + + ED_editors_init(C); + WM_operatortype_last_properties_clear_all(); /* important to do before NULL'ing the context */ ```

Conrad Dueck commented

2019-03-04 20:49:26 +01:00

Added subscriber: @ConradDueck

blender-admin commented

2019-03-05 19:17:36 +01:00

This issue was referenced by d31b2f8549

This issue was referenced by d31b2f854954838fb849b5b0be0011d792eecb43

Brecht Van Lommel commented

2019-03-05 19:23:19 +01:00

Changed status from 'Open' to: 'Resolved'

Brecht Van Lommel closed this issue

2019-03-05 19:23:19 +01:00

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Function from Python not being loaded for Driver when project opened #61063