Add doc about RT support

docs/behind_scenes/d3d12_support.rst

@@ -20,6 +20,8 @@ RenderDoc has initial support for D3D12, but it contains some caveats. In additi
 * RenderDoc assumes that even if multiple GPUs are present, that only one will be used - i.e. NodeMask is always 0. Multiple queues are supported.
 * RenderDoc captures may not be portable between different systems, only currently supporting capture and replay on the same or similar enough machines.
 
+For more information about RenderDoc's raytracing support see :doc:`raytracing`.
+
 RenderDoc extensions
 --------------------
 

docs/behind_scenes/index.rst

@@ -8,3 +8,4 @@ Behind the scenes
     opengl_support
     vulkan_support
     d3d12_support
+    raytracing

docs/behind_scenes/raytracing.rst

@@ -0,0 +1,8 @@
+Raytracing Support
+==================
+
+The primary goal of raytracing handling in RenderDoc is to allow for debugging the rest of the normal work while an application has raytracing enabled. The raytracing work itself will be entirely opaque and there will be no way to introspect any bindings, shaders, or what it is doing at even a basic or rudimentary level - RenderDoc does not support debugging anything to do with raytracing in either Vulkan or D3D12.
+
+Any raytracing work in the captured frames will be recorded and the results accurately reflected in order to allow debugging of any other non-raytracing work that happens as normal. This means the contents of any resources updated by raytracing calls will be correct in subsequent normal graphics work.
+
+At present there is no plan to expand this support, and this is a deliberate decision to make it very clear what is and is not supported in RenderDoc. For this reason the support will not be expanded incrementally to avoid a situation where raytracing debugging exists but is in extremely poor shape. Since raytracing is an entirely separate/dedicated black box subset of APIs the tooling requirements for it are quite different to normal graphics work and would require significant resource investment.

docs/behind_scenes/vulkan_support.rst

@@ -36,6 +36,8 @@ RenderDoc has support for Vulkan version 1.3, as well as a number of extensions,
 * RenderDoc assumes that even if multiple GPUs are present, that only one VkDevice will be created and used.
 * RenderDoc captures will in general not be portable between different systems, only currently supporting capture and replay on the same or similar enough machines.
 
+For more information about RenderDoc's raytracing support see :doc:`raytracing`.
+
 Android
 -------