I need to do some more testing but I think this also solves #78544

I think there should be 100% a fallback as the mobile renderer works better on older pc and it also has to support mobile, which nowadays it vulkan support is not the best.

@Saul2022 agreed though I'd like to mark all the "todos" for future PRs. This is an important fix I'd like to get into 4.1 and the fix window closes Monday. As currently resolving doesn't work plus we have a number of validation errors that are solved by this, this is a step forward and shouldn't break anything that isn't already broken.

@clayjohn @akien-mga I'm marking this for review due to the above reason if you guys are ok with that.

As discussed on chat, let's not rush it now, but this is a good candidate for 4.1.1 once finalized and merged for 4.2.

Does this resolve #78785?

@Calinou I don't think so, but that is one I need to find time for

Is this still getting merged? I also got the same issue on my XR project so I wonder if there are any workarounds too.

@BastiaanOlij Do you plan to update this one now that the subpasses merge PR got upstreamed?

@Stratapeum this got stuck because we have no fallback if the extension is not supported. I'm not sure if @DarioSamo is looking into this as resolving depth buffer has become important for other purposes.

cc @clayjohn is it worth reviving this as is or do you guys have other plans around the work that has recently been done?

cc @clayjohn is it worth reviving this as is or do you guys have other plans around the work that has recently been done?

I don't have any plans for working on this myself if that is what you are asking.

So far only tested on desktop (Nvidia 40xx), will do more testing, but it resolves depth just fine using the extension:

I'm out of the loop for a while so tested for both 4.6-dev1 and this PR artifacts, using the Windows editor with the Android template.

For the both versions, the old Samsung Galaxy s10 (2019) and the Samsung Galaxy s25 seems to work with and without MSAA 4x. for 4.5-stable the depth buffer doens't work with MSAA 4x as expected.

Not sure why it works on 4.6-dev1 (Edit: just found #108636, that's awesome), but everything seems to run ok. Also tested my personal project, and shaders that depends on the depth buffer seems to work without issues.

Excellent job!

Bump for progress. This is required before we can enable MSAA on visionOS immersive rendering.

Bump for progress. This is required before we can enable MSAA on visionOS immersive rendering.

Are you sure? This is an optimization for certain GPUs, but doesn't change functionality

Are you sure? This is an optimization for certain GPUs, but doesn't change functionality

The only thing I need is a correctly resolved depth buffer. VisionOS needs depth output to display correctly. Here is an example showing what will happen if depth is not correctly configured.

Depth buffer is not correctly resolved in current implementation. I tried other workarounds, including force scene_state.used_depth_texture = true, call RenderingDevice::texture_resolve_multisample for depth buffer. They all don't work. I don't know how these methods behave on other platforms. I can only confirm they have some issue on metal.

So yes, there can be two way to fix this. One is fixing manual depth resolve on metal (for layered depth texture), the other one is implement hardware depth resolve for metal after this PR get merged.

It is very easy to implement depth resolve on metal, and I have a working implementation. Hardware depth resolve should be supported on all apple platforms current godot targets. Its support starts from A9 chip, used ten years ago in iPhone 6s. iPhones older than that does not support iOS 14, the min target iOS version of godot.

So implement hardware depth resolve is my goto solution. It is faster, more general, does not introduce platform specific code in forward mobile renderer. I don't see the value to fix manual depth resolve on metal.

I don't know why this PR is stalled from merging if this is merely an optimization. If you worry about extension coverage, this extension have more than 70% coverage on android, 100% coverage on iOS (moltenVK) if you check vulkan database.

@huisedenanhai indeed very important for VisionPro however the solution there is found inside the metal driver, not related to Vulkan.

indeed very important for VisionPro however the solution there is found inside the metal driver, not related to Vulkan.

It is not related to vulkan. But the fix in metal driver needs new RenderingDevice depth attachment resolve APIs, which is introduced in this pr.

indeed very important for VisionPro however the solution there is found inside the metal driver, not related to Vulkan.

It is not related to vulkan. But the fix in metal driver needs new RenderingDevice depth attachment resolve APIs, which is introduced in this pr.

Ah, gotcha!

I got a few small changes left to do but we should be able to move on it quickly.

@clayjohn I've added in the TEXTURE_USAGE_DEPTH_RESOLVE_ATTACHMENT_BIT change. As far as I can tell this is working as expected.

There are a few XR use cases waiting on this so it would be good if you could have a peek at it :)

Thanks!

With this PR, I got a lots of error in console output (Windows 11) :

Godot Engine v4.6.dev.custom_build.2edc43df8 (2025-11-20 17:10:48 UTC) - https://godotengine.org
Vulkan 1.4.312 - Forward+ - Using Device #0: NVIDIA - NVIDIA GeForce RTX 3060

ERROR: Format 'D24_Unorm_S8_Uint' does not support usage as storage image.
at: (servers\rendering\rendering_device.cpp:1033)
ERROR: Attempted to name invalid ID: 0
at: RenderingDevice::set_resource_name (servers\rendering\rendering_device.cpp:6360)
ERROR: Condition "p_named_texture.texture.is_null()" is true.
at: RenderSceneBuffersRD::update_sizes (servers\rendering\renderer_rd\storage_rd\render_scene_buffers_rd.cpp:82)
ERROR: Texture (binding: 3) should provide one ID referencing a texture (IDs provided: 0).
at: (servers\rendering\rendering_device.cpp:3724)
ERROR: Condition "named_texture.texture.is_null()" is true. Returning: RID()
at: RenderSceneBuffersRD::get_texture_slice_view (servers\rendering\renderer_rd\storage_rd\render_scene_buffers_rd.cpp:431)
ERROR: Image (binding: 0) should provide one ID referencing a texture (IDs provided: 0).
at: (servers\rendering\rendering_device.cpp:3769)
ERROR: Condition "rid.is_null()" is true. Returning: rid
at: UniformSetCacheRD::_allocate_from_uniforms (.\servers/rendering/renderer_rd/uniform_set_cache_rd.h:120)
ERROR: Parameter "uniform_set" is null.
at: RenderingDevice::compute_list_bind_uniform_set (servers\rendering\rendering_device.cpp:5364)
ERROR: Uniforms were never supplied for set (1) at the time of drawing, which are required by the pipeline.
at: (servers\rendering\rendering_device.cpp:5453)
ERROR: Condition "named_texture.texture.is_null()" is true. Returning: RID()
at: RenderSceneBuffersRD::get_texture_slice_view (servers\rendering\renderer_rd\storage_rd\render_scene_buffers_rd.cpp:431)
ERROR: Image (binding: 0) should provide one ID referencing a texture (IDs provided: 0).
at: (servers\rendering\rendering_device.cpp:3769)
ERROR: Condition "rid.is_null()" is true. Returning: rid
at: UniformSetCacheRD::_allocate_from_uniforms (.\servers/rendering/renderer_rd/uniform_set_cache_rd.h:120)
ERROR: Parameter "uniform_set" is null.
at: RenderingDevice::compute_list_bind_uniform_set (servers\rendering\rendering_device.cpp:5364)
ERROR: Uniforms were never supplied for set (1) at the time of drawing, which are required by the pipeline.
at: (servers\rendering\rendering_device.cpp:5453)
ERROR: Condition "named_texture.texture.is_null()" is true. Returning: RID()
at: RenderSceneBuffersRD::get_texture_slice_view (servers\rendering\renderer_rd\storage_rd\render_scene_buffers_rd.cpp:431)
ERROR: Image (binding: 0) should provide one ID referencing a texture (IDs provided: 0).
at: (servers\rendering\rendering_device.cpp:3769)

To reproduce:

• Create empty project, create a 3d scene.
• Create a MeshInstance3D node.
• Create a BoxMesh.
• Click the BoxMesh data resource to see the preview.
  Error with keep output in viewport.