Vulkan: Screen space reflections weirdly rotated with orthogonal cameras

[ghost]

Godot version

v4.0.3.stable.official [5222a99]

System information

Mac Ventura - Vulkan API 1.2.231 - Forward+ - Apple M1

Issue description

SSR doesn't appear correctly with orthographic cameras, the reflections are rotated around seemingly inverse to the camera.

There's a similar issue #49204, however the previous one is for Godot 3.5 and the workarounds no longer work. The editor camera no longer works properly, and neither does moving the camera far away. I believe this may be a different (though likely related) problem. Hopefully this is okay.

Screenshot:

Best regards.

Steps to reproduce

1. Switch editor to orthographic mode and rotate the camera around, reflections are weird (in previous issue the editor camera was unaffected)
2. Preview OrthoCamera -- this is set to use the previous workaround of moving the camera far away, however this doesn't seem to work anymore

Minimal reproduction project

SSRTest.zip

[Calinou]

• Related to Screen space reflections behaving strangely on orthographic Camera #49204.

[farfalk]

This still happens in 4.3beta2, with some additional weird visual glitches happening only with SSR enabled

[mertkasar]

Also suffering this issue in my project. Reproducible in every v4.x.x release.

Using negative camera space positions solves the wrong reflection rotations in orthogonal cameras. Turns out the rotations were actually reversed in here:

godot/servers/rendering/renderer_rd/shaders/effects/screen_space_reflection_inc.glsl

Lines 22 to 26 in 26d1577

	if (params.orthogonal) {
	return vec3((screen_pos.xy * params.proj_info.xy + params.proj_info.zw), z);
	} else {
	return vec3((screen_pos.xy * params.proj_info.xy + params.proj_info.zw) * z, z);
	}

So, line 23 becomes:

return vec3(-(screen_pos.xy * params.proj_info.xy + params.proj_info.zw), z);

However, issue #49204 from branch 3.x appeared here, too. Reflections gain perspective in orthographic cameras as the z-position of the camera lowers. Here is a minimal reproduction of this in a custom build with the fix above:

(in-game camera sits at z:25)

Whereas the expected behavior is much more like this:

(orthogonal editor camera, which probably sits at much greater z)

MRP:
ssr_orthographic_mrp.zip

@Geometror's workaround mentioned in the other issue can also be applied here once this issue is fixed. But still, reflections in an orthogonal camera should be… orthographic, I guess 😅 Perspective can be omitted entirely for SSR with orthogonal cameras.

[Calinou]

Good catch 🙂

Using negative camera space positions solves the wrong reflection rotations in orthogonal cameras. Turns out the rotations were actually reversed:

Can you open a pull request for this?