Vulkan: Shader that uses TIME does not force editor to continuously update

[t3nk3y]

Godot version

v4.0.dev.custom_build [e599f1b]

System information

Ubuntu 21.04

Issue description

When using a shader that uses TIME to provide animation, the editor should continuously update the viewport as it did Godot 3, however in Godot 4, it is not doing so.

Doing anything that refreshes the viewport, such as scrolling or zooming will update the shader.

This can be worked around by enabling "Update Continuously" in the Editor settings.

Here is how it should work:

Here is how it DOES work:

Steps to reproduce

Place any object in the 3D editor that has a ShaderMaterial that includes TIME to provide animation.

NOTE: Be sure "Update Continuously" is off in the Editor settings, as this will work around the issue.

Minimal reproduction project

This project has an example. Just load the project and the main scene should immediately fail to work right.(so long as update continuously is not checked in editor settings)
ShaderEditorIssueExample.zip

If anyone likes the little shader I put in here, feel free to use it, no credits needed.

[Zireael07]

I believe this has been turned off for performance reasons?

[Calinou]

I believe this has been turned off for performance reasons?

This was likely not done intentionally, as this is not the behavior in 3.x. A proper way to fix this would be #43011, as this is something that needs to be consciously enabled by the user.

[t3nk3y]

I agree that #43011 would be a sensible fix. Feel free to close this issue if you want.

[Calinou]

I'll leave this issue open as the lack of updating by default still feels weird in practice.

[clayjohn]

We need to make a redraw_request when a material has the uses_time property set to true. Here is how it is done in 2D

godot/servers/rendering/renderer_rd/renderer_canvas_render_rd.cpp

Lines 1372 to 1374 in 5f69218

	if (md->shader_data->uses_time) {
	time_used = true;
	}

godot/servers/rendering/renderer_rd/renderer_canvas_render_rd.cpp

Lines 1472 to 1474 in 5f69218

	if (time_used) {
	RenderingServerDefault::redraw_request();
	}

and in sky shaders:

godot/servers/rendering/renderer_rd/renderer_scene_sky_rd.cpp

Lines 1095 to 1099 in 036b7a0

	if (shader_data->uses_time && p_scene_render->time - sky->prev_time > 0.00001) {
	sky->prev_time = p_scene_render->time;
	sky->reflection.dirty = true;
	RenderingServerDefault::redraw_request();
	}

[jinyoung-lim]

I'm new to open source and would love to take a stab at this issue.

[zedutch]

@Calinou @clayjohn I think I've found a way to solve this. Should I wait for an update from @jinyoung-lim or can I go ahead and submit a pull request?

[jinyoung-lim]

Hey @zedutch - feel free to go ahead for a pull request. I got busy with other things and am not ready for a pull request.