Improve handling of the format of the VRS image

- Validate format conservatively. (This is to have VRS images created regardless whether VRS attachments are supported, which avoids errors in places where the code assumes such images were created on low-spec GPUs.)
- Create a non-layered default VRS image, which is what Vulkan (and D3D12, by the way) expect.

drivers/vulkan/rendering_device_vulkan.cpp

@@ -1835,7 +1835,8 @@ RID RenderingDeviceVulkan::texture_create(const TextureFormat &p_format, const T
 			ERR_FAIL_V_MSG(RID(), "Format " + format_text + " does not support usage as atomic storage image.");
 		}
 
-		if (p_format.usage_bits & TEXTURE_USAGE_VRS_ATTACHMENT_BIT && !(flags & VK_FORMAT_FEATURE_FRAGMENT_SHADING_RATE_ATTACHMENT_BIT_KHR)) {
+		// Validation via VK_FORMAT_FEATURE_FRAGMENT_SHADING_RATE_ATTACHMENT_BIT_KHR fails if VRS attachment is not supported.
+		if (p_format.usage_bits & TEXTURE_USAGE_VRS_ATTACHMENT_BIT && p_format.format != DATA_FORMAT_R8_UINT) {
 			ERR_FAIL_V_MSG(RID(), "Format " + format_text + " does not support usage as VRS attachment.");
 		}
 	}
@@ -3358,7 +3359,8 @@ bool RenderingDeviceVulkan::texture_is_format_supported_for_usage(DataFormat p_f
 		return false;
 	}
 
-	if (p_usage & TEXTURE_USAGE_VRS_ATTACHMENT_BIT && !(flags & VK_FORMAT_FEATURE_FRAGMENT_SHADING_RATE_ATTACHMENT_BIT_KHR)) {
+	// Validation via VK_FORMAT_FEATURE_FRAGMENT_SHADING_RATE_ATTACHMENT_BIT_KHR fails if VRS attachment is not supported.
+	if (p_usage & TEXTURE_USAGE_VRS_ATTACHMENT_BIT && p_format != DATA_FORMAT_R8_UINT) {
 		return false;
 	}
 

servers/rendering/renderer_rd/storage_rd/texture_storage.cpp

@@ -398,9 +398,8 @@ TextureStorage::TextureStorage() {
 		tformat.format = RD::DATA_FORMAT_R8_UINT;
 		tformat.width = 4;
 		tformat.height = 4;
-		tformat.array_layers = 1;
 		tformat.usage_bits = RD::TEXTURE_USAGE_COLOR_ATTACHMENT_BIT | RD::TEXTURE_USAGE_VRS_ATTACHMENT_BIT | RD::TEXTURE_USAGE_SAMPLING_BIT | RD::TEXTURE_USAGE_STORAGE_BIT | RD::TEXTURE_USAGE_CAN_UPDATE_BIT;
-		tformat.texture_type = RD::TEXTURE_TYPE_2D_ARRAY;
+		tformat.texture_type = RD::TEXTURE_TYPE_2D;
 
 		Vector<uint8_t> pv;
 		pv.resize(4 * 4);