Unreal Engine Issues

Placed render targets are not initialized properly in D3D12

Virtual Texture Collection Indexing Not Working

Textures at an index, other than 0, cannot be sampled from a Virtual Texture Collection in a material. When using the Texture Collection and Texture Object From Collection material nodes, with a Vir ...

HZB Occlusion causes large stalls on the render thread

HZB Occlusion causes large stalls (greater than 5ms seen) on the render thread due to an RHI flush. This is caused by the following code in FDynamicRHI::RHIMapStagingSurface_RenderThread which force ...

The Console Command list printed by using "Help" misses alot items in 5.6

FD3D12BindlessResourceManager::GrowCPUHeap will cause GPU heap activation whether it's needed or not

The ctor of FD3D12BindlessResourceManager implies that GPU heap activation is intended to occur lazily with ERHIBindlessConfiguration::RayTracingShaders, however any call to FD3D12BindlessResourceMa ...

Enabling STATS causes RenderThread to wait for GPU

The licensee noticed that in Development builds, the Render thread times are suspiciously similar to GPU times, and the same thing happens when enabling FORCE_USE_STATS in Test configuration. The is ...

Missing PSO Precaches in the engine

A licensee wanted to report some missing PSO Precaching they found, which they have fixed locally: 1. UCableComponent doesn't implement CollectPSOPrecacheData or call CheckPSOPrecachingAndBoostPri ...

Performance slowdown when ray tracing is disabled due to SetResidencyPriority

When a game is compiled with ray tracing disabled (D3D12_RHI_RAYTRACING=0) and the GPU the game is running on becomes low on VRAM, frame time is negatively impacted and doesn't recover. The D3D12_RH ...

Bindless Textures in active use are able to be garbage collected

It is possible for textures referenced in the bindless texture data assets that are actively used in materials being rendered in the active viewport to be garbage collected. This results in the mat ...

GPU event descriptions are not properly formatted in Insight

Context Unreal Insights displays Timing Insights that can include GPU timing information. Rendering code such as FDeferredShadingSceneRenderer::RenderPrePass() generate such events.Problem Certain f ...