UILayout.template_node_view() doesn't render UI properly #99569

New Issue

System Information
Operating system: Affected on Windows 10 and macOS (Windows 11 not tested, works on Linux)
Graphics card: GTX 1080 x2

Blender Version
Broken: 2.93 and above
Worked: 2.92

Short description of error
When using layout.template_node_view() on a custom node network the inputs don't render properly in the UI. This happens on Windows and macOS but not on Linux. It works in 2.92 but not 2.93 and above.

UI in 2.92

UI in 2.93

This is harder to reproduce on your own, but here are some links to the specific lines in my code that are causing the issue to help give you some context. This code is VERY similar to the internal Python code for EEVEE/Cycles, so I'm not sure why it's working for those renderers and not for mine.

This is a customized panel_node_draw() function, where template_node_view() is actually called.
b11f577103/ui/utils.py (L35)

This is the panel UI code where panel_node_draw() is called.
b11f577103/ui/material.py (L101)

Exact steps for others to reproduce the error

Open attached .blend file
Run script
Note the panel Node UI Bug Panel in {nav Properties > Render panel}

uilayout_bug_example.blend

**System Information** Operating system: Affected on Windows 10 and macOS (Windows 11 not tested, works on Linux) Graphics card: GTX 1080 x2 **Blender Version** Broken: 2.93 and above Worked: 2.92 **Short description of error** When using `layout.template_node_view()` on a custom node network the inputs don't render properly in the UI. This happens on Windows and macOS but not on Linux. It works in 2.92 but not 2.93 and above. UI in 2.92 ![image.png](https://archive.blender.org/developer/F13279176/image.png) UI in 2.93 ![image.png](https://archive.blender.org/developer/F13279157/image.png) This is harder to reproduce on your own, but here are some links to the specific lines in my code that are causing the issue to help give you some context. This code is VERY similar to the internal Python code for EEVEE/Cycles, so I'm not sure why it's working for those renderers and not for mine. This is a customized `panel_node_draw()` function, where `template_node_view()` is actually called. https://github.com/lunadigital/btoa/blob/b11f577103f9e841d25de96bf865c31f771bd00c/ui/utils.py#L35 This is the panel UI code where `panel_node_draw()` is called. https://github.com/lunadigital/btoa/blob/b11f577103f9e841d25de96bf865c31f771bd00c/ui/material.py#L101 **Exact steps for others to reproduce the error** - Open attached .blend file - Run script - Note the panel `Node UI Bug Panel` in {nav Properties > Render panel} ![image.png](https://archive.blender.org/developer/F13286105/image.png) [uilayout_bug_example.blend](https://archive.blender.org/developer/F13286032/uilayout_bug_example.blend) ---

Added subscriber: @lunadigital

Added subscriber: @mano-wii

Changed status from 'Needs Triage' to: 'Needs User Info'

Thanks for the report, but in order for us to forward the report to the developers, we require clear steps to reproduce the problem and, in this case, a simple script (containing only the necessary lines).

While this is a real issue, the real cause of it doesn't seem so clear, and due to the large flow of reports, we require the bug reporter to narrow down the problem.

So can you provide the steps and a small code snippet showing the problem?

A guideline for making a good bug report can be found at https://wiki.blender.org/wiki/Process/Bug_Reports

Thanks for the report, but in order for us to forward the report to the developers, we require clear steps to reproduce the problem and, in this case, a simple script (containing only the necessary lines). While this is a real issue, the real cause of it doesn't seem so clear, and due to the large flow of reports, we require the bug reporter to narrow down the problem. So can you provide the steps and a small code snippet showing the problem? A guideline for making a good bug report can be found at https://wiki.blender.org/wiki/Process/Bug_Reports

I managed to take the "Custom Nodes" example that comes with Blender and made an example that reproduces what I'm seeing. If you run the script in this blend file, you'll see a custom node graph and a panel in the Properties > Render panel called "Node UI Bug Panel". On Linux, it displays as expected, with the socket values to the right of the socket icon. On Windows and macOS, it remains blank like the images I shared above.uilayout_bug_example.blend

I managed to take the "Custom Nodes" example that comes with Blender and made an example that reproduces what I'm seeing. If you run the script in this blend file, you'll see a custom node graph and a panel in the Properties > Render panel called "Node UI Bug Panel". On Linux, it displays as expected, with the socket values to the right of the socket icon. On Windows and macOS, it remains blank like the images I shared above.[uilayout_bug_example.blend](https://archive.blender.org/developer/F13286032/uilayout_bug_example.blend)

For what it's worth, it seems like it only happens on custom sockets. Internal Blender socket types seem to work okay.

Changed status from 'Needs User Info' to: 'Needs Triage'

Changed status from 'Needs Triage' to: 'Confirmed'

Thanks for simplifying. I can confirm the problem. But I can't replicate it on 2.93.
It looks like the problem was introduced sometime between 4f387e66ac, 35124acd19 in Blender 3.1 and backported to 3.0

Thanks for simplifying. I can confirm the problem. But I can't replicate it on 2.93. It looks like the problem was introduced sometime between 4f387e66ac, 35124acd19 in Blender 3.1 and backported to 3.0

It's interesting you can't reproduce it on 2.93...I wonder what's going on there.

In any case, I'm glad we can start tracking it now - let me know if I can provide anything else!

It's interesting you can't reproduce it on 2.93...I wonder what's going on there. In any case, I'm glad we can start tracking it now - let me know if I can provide anything else!

I don't know if this is related, but I also noticed the custom node sockets appear to have a black stroke outline in Linux, but a gray outline in Windows. At first I thought it was just how custom sockets rendered in general but now I'm wondering if this is related to the rendering issues above.

This is still an issue in 3.6. To be honest, custom shader graphs now feel like a second class experience because of it, which is frustrating. What can I do to push this forward? @mano-wii

It was fixed in 4.0 (main).
For 3.6 the fix was put on the list To Be Backported.
Blender LTS: Maintenance Task 3.6

It was fixed in 4.0 (main). For 3.6 the fix was put on the list To Be Backported. [Blender LTS: Maintenance Task 3.6](https://projects.blender.org/blender/blender/issues/109399)

Download

What's New

Blender Studio

Manual

Developers Blog

Documentation

Benchmark

Blender Conference

Development Fund

One-time Donations

UILayout.template_node_view() doesn't render UI properly #99569