# VKD3D-Proton 3.1 adds descriptor heaps, DXR 1.2, Shader Model 6.9 ahead of major 3.2 cycle

> **Key takeaway:** Valve's Direct3D 12-to-Vulkan translation layer gets a stable checkpoint release with new graphics capabilities before a significant feature push for version 3.2.

**Published:** 2026-10-28T10:27:21+00:00 
**Source:** Phoronix Benchmarks & Drivers 
**Category:** kernel-os 
**Canonical URL:** https://fosswire.org/news/vkd3d-proton-31-adds-descriptor-heaps-dxr-12-shader-model-69.html 

## Summary
Valve Linux developer Hans-Kristian Arntzen has released VKD3D-Proton 3.1, a stable milestone that introduces several new graphics capabilities while serving as the final checkpoint before an extensive development cycle for version 3.2. The release adds descriptor heap support via VK_EXT_descriptor_heap, KHR_opacity_micromap for DXR 1.2 ray tracing exposure, and Shader Model 6.9 compatibility, alongside expanded NVIDIA NVAPI intrinsic support in the DXIL-SPIRV compiler and default-enabled view instancing for broader game compatibility.

Arntzen explicitly positioned 3.1 as the last stable release before VKD3D-Proton enters what he described as "uncharted territory" for 3.2 development, signaling substantial architectural changes ahead. The release also includes performance optimizations, bug fixes, and game-specific workarounds that improve the experience for Direct3D 12 titles running through Proton on SteamOS and Linux desktop systems.

## Graphics pipeline and API changes in VKD3D-Proton 3.1
- **Descriptor heaps:** VK_EXT_descriptor_heap support is implemented but not yet enabled by default due to driver quality concerns, indicating a staged rollout for this memory management optimization.
- **Ray tracing advancement:** KHR_opacity_micromap support enables exposure of DXR 1.2 capabilities when the underlying Vulkan driver supports the extension, expanding hardware-accelerated ray tracing compatibility.
- **Shader model upgrade:** Shader Model 6.9 support extends the DXIL translation capabilities, allowing newer Direct3D 12 games and effects to compile through to SPIR-V.
- **NVAPI intrinsics:** Additional NVIDIA NVAPI intrinsics are now handled in the DXIL-SPIRV code path, improving feature parity for NVIDIA hardware running on Linux.
- **AgilitySDK and view instancing:** AgilitySDK 619 features are exposed, and view instancing is enabled by default to accommodate more games that depend on this multi-view rendering optimization.

## Why it matters
For Steam Deck and Linux desktop gamers, VKD3D-Proton 3.1 represents an immediate compatibility improvement for newer Direct3D 12 titles while establishing the baseline for more substantial changes in 3.2. The explicit framing of this as a "last stable release" before major development suggests Linux gaming users may want to monitor 3.2 development closely, as significant architectural shifts could temporarily introduce instability or dramatically expand supported game catalogs.