Crash when trying to use D3D12 in a build that does not have Direct3D 12 support enabled

[Mostafa808]

Tested versions

• Reproducible in: custom builds origin/4.3, origin/4.4, origin/master, compiled by SCons and visual studio with dev_build symbols.
• Not Reproducible in: public official build 4.4.

System information

Windows 10

Issue description

A godot project was made in 4.3 official version on windows 11 I think. It was shared with me. The official godot 4.4 build is working fine. I mean it is not crashing on startup. But when I try to open the project with my custom build from godot source code. It crashes of rendering settings in project.godot. I think it was because it d3d12 driver in one of the settings:

[rendering]

rendering_device/driver.windows="d3d12"
textures/vram_compression/import_etc2_astc=true
textures/default_filters/anisotropic_filtering_level=0

Yes, I have directX 11 driver, I think, on my windows not directX12 but again because this was not originally created by me. I tried to debug the code from the main entry point and for some reasons in

rendering_server_default.cpp file
RenderingServerDefault::_init() function
RSG::rasterizer = RendererCompositor::create(); line

RendererCompositor *(*RendererCompositor::_create_func)() = nullptr;
bool RendererCompositor::low_end = false;

RendererCompositor *RendererCompositor::create() {
	return _create_func();
}

_create_func() returns null, actually it tries to access the memory at null resulting in memory access violation and the app is crashed.
I removed this line from project.godot and this issue was resolved for me.

rendering_device/driver.windows="d3d12"

[rendering]

textures/vram_compression/import_etc2_astc=true
textures/default_filters/anisotropic_filtering_level=0

I still think a setting in project.godot should not crash the custom build engine!
Like it should produce a warning or something.

Steps to reproduce

1. on windows 10 compile using godot source using SCons for visual studio.
2. scons platform=windows vsproj=yes dev_build=yes
3. make project.godot has a driver.windows that does not exist/supported on your machine for your godot project.
4. debug the custom editor on this project. It crashes on start for me.

Minimal reproduction project (MRP)

In my project.godot file:

[rendering]

rendering_device/driver.windows="d3d12"
textures/vram_compression/import_etc2_astc=true
textures/default_filters/anisotropic_filtering_level=0

I changed it to:

[rendering]

textures/vram_compression/import_etc2_astc=true
textures/default_filters/anisotropic_filtering_level=0

Now, the issue is solved for me.

[clayjohn]

You need to build with support for d3d12. Take a look at the docs for compiling with support for d3d12

[Mostafa808]

I assume I was confused by this statement at first:

By default, builds of Godot do not contain support for the Direct3D 12 graphics API.

The official builds are indeed compiled with d3d12 option. I thought otherwise because of "By default". I wish the engine would ignore this option and print a warning if compiled without d3d12. Maybe later.
Anyway, thanks for your help! I appreciate it!

[Calinou]

I still think the crash is unintended here, and it should fall back to Vulkan as D3D12 is not supported by the current build. We already have such fallback logic in place; we should make sure it's always used regardless of GPU support in builds that have D3D12 disabled at compile-time.

The automatic fallback will always print a message when it occurs, but maybe it's worth making an additional print in this case to state that the current build has D3D12 support disabled.