Sky: Adapt radiance size if AUTOMATIC_MODE resolves to REALTIME

[Breush]

• Bugsquad edit, fixes: Vulkan Forward+: Visual glitch appears in the radiance map at sizes higher or lower than the default #76166

[Calinou]

Tested locally, it works as expected. Code looks good to me.

[akien-mga]

For the record, your commit seems not to be linked to your GitHub account. See: Why are my commits linked to the wrong user? for more info.

[Breush]

For the record, your commit seems not to be linked to your GitHub account. See: Why are my commits linked to the wrong user? for more info.

Thanks, I didn't notice, updated my config.

[clayjohn]

I don't think this is the correct fix for two reasons:

1. material_get_data() isn't thread safe. So this change introduces a race condition when using multithreaded rendering
2. This is hardcoded to only work with the Forward+ and Mobile rendering methods. It will fail when using Compatibility.

I think the correct fix is to not fall back to the realtime mode when the radiance size is not 256. I.e. check for radiance size here:

godot/servers/rendering/renderer_rd/environment/sky.cpp

Lines 1253 to 1256 in 61598c5

	if (sky_mode == RS::SKY_MODE_AUTOMATIC) {
	if (shader_data->uses_time || shader_data->uses_position) {
	update_single_frame = true;
	sky_mode = RS::SKY_MODE_REALTIME;

and here:

godot/drivers/gles3/rasterizer_scene_gles3.cpp

Lines 914 to 917 in 61598c5

	if (sky_mode == RS::SKY_MODE_AUTOMATIC) {
	if (shader_data->uses_time || shader_data->uses_position) {
	update_single_frame = true;
	sky_mode = RS::SKY_MODE_REALTIME;

e.g. if ((shader_data->uses_time || shader_data->uses_position) && sky->radiance_size == 256)

[Breush]

I don't think this is the correct fix for two reasons: (...)

Got it. I will update this PR on Wednesday with the suggested fix.

[clayjohn]

Looks great!

Note for maintainers, this should be good for cherry picking

[akien-mga]

Thanks! And congrats for your first merged Godot contribution 🎉

[akien-mga]

Cherry-picked for 4.3.1.