Rendering Pipeline Overview (this sample)

This engine uses Vulkan Dynamic Rendering with a small, readable sequence of passes. The order is deliberate: it keeps tone mapping explicit, keeps transparency sane, and makes it easy to plug in optional features like planar reflections or the Ray Query compute path.

The pass order

Optional reflection pass (off‑screen):
- Mirror the camera across a plane (e.g., floors or windows).
- Render opaque geometry into a reflection render target (color + depth).
- Transition the reflection image to SHADER_READ_ONLY_OPTIMAL for the next frame.
Opaque to off‑screen color:
- Render all opaque objects into an off‑screen color image (opaqueSceneColor).
- Depth is read/write as usual (or read‑only if you ran a depth pre‑pass).
Composite to swapchain:
- End the opaque rendering.
- Transition opaqueSceneColor to SHADER_READ_ONLY_OPTIMAL.
- Begin a new rendering instance targeting the swapchain image and draw a full‑screen pass that samples the off‑screen color (tone mapping included).
Transparent on top:
- Keep the swapchain image as the color attachment and bind the scene depth.
- Render transparent objects (glass/liquids) back‑to‑front.
- Glass samples the prior frame’s reflection texture when enabled.
UI:
- Render the UI on top.
- Transition the swapchain image to PRESENT_SRC_KHR after ending rendering.

Where to look in the code

Main render loop + pass ordering:
- renderer_rendering.cpp
Pipeline setup (dynamic rendering attachments, layouts, formats):
- renderer_pipelines.cpp
Composite pass shader (tone mapping + presentation):
- shaders/composite.slang
PBR shading utilities shared by multiple pipelines:
- shaders/pbr.slang
- shaders/pbr_utils.slang
- shaders/lighting_utils.slang

Why this shape

A single off‑screen buffer makes tone mapping explicit and avoids gamma‑incorrect copy paths.
Transparent ordering stays simple because the swapchain is the current color attachment in that pass.
The reflection pass is optional and self‑contained.

Future work ideas

If you want to take this pipeline further:

Add a depth pre-pass for heavy scenes (helps early-z and enables more accurate Forward+ clustering).
Add a lightweight bloom chain that runs between the off-screen opaque pass and the composite.
Add a dedicated transparent resolve path (weighted blended OIT) if you need lots of overlapping glass.
Demonstrate hybrid rendering by calling ray queries from a raster shader (reflection probe, shadow test, or glass-only reflections).