# \#Path-Tracing **URL:** https://forums.unrealengine.com/tag/path-tracing/11338.md [Latest](https://forums.unrealengine.com/latest.md) · [Categories](https://forums.unrealengine.com/categories.md) · [Tags](https://forums.unrealengine.com/tags.md) --- ## [Runtime Path Tracing not rendering anymore](https://forums.unrealengine.com/t/runtime-path-tracing-not-rendering-anymore/2853370)
**Author:** [@Miguel1900](https://forums.unrealengine.com/u/Miguel1900)\ **Replies:** 0\ **Last updated:** [November 10, 2026, 2:41pm UTC](https://forums.unrealengine.com/t/runtime-path-tracing-not-rendering-anymore/2853370 "2026-11-10T14:41:43Z")
Summary Since 5.6, if you are executing offline Path Tracing rendering during runtime, it won’t finish the rendering, turning into a black screen at some point. Working perfectly fine in 5.5. What Type of Bug are you ex… --- ## [Managing complex lighting workflows in Unreal Engine - Lights, Emissive Materials & Cinematics](https://forums.unrealengine.com/t/managing-complex-lighting-workflows-in-unreal-engine-lights-emissive-materials-cinematics/2842612)
**Author:** [@Live000](https://forums.unrealengine.com/u/Live000)\ **Replies:** 0\ **Last updated:** [October 19, 2026, 9:41pm UTC](https://forums.unrealengine.com/t/managing-complex-lighting-workflows-in-unreal-engine-lights-emissive-materials-cinematics/2842612 "2026-10-19T21:41:48Z")
Hi everyone, One of the recurring challenges in complex Unreal Engine productions isn’t necessarily setting up individual lights. It’s maintaining consistent lighting behavior across multiple light sources, emissive mat… --- ## [Ray Tracing PSO Issue with Imported Mesh](https://forums.unrealengine.com/t/ray-tracing-pso-issue-with-imported-mesh/2836799)
**Author:** [@BlastIsDead](https://forums.unrealengine.com/u/BlastIsDead)\ **Replies:** 7\ **Last updated:** [October 7, 2026, 8:11pm UTC](https://forums.unrealengine.com/t/ray-tracing-pso-issue-with-imported-mesh/2836799 "2026-10-07T20:11:58Z")
I have a rock Mesh (~700k polygons) imported from Houdini. The object rendered just fine in Lumen. However, when I switched to Path Tracing, I got a message “Ray Tracing pso is not ready yet using fallback.” So far, I h… --- ## [Pathtracer and Niagara-Particles - since when do they work together? :)](https://forums.unrealengine.com/t/pathtracer-and-niagara-particles-since-when-do-they-work-together/569386)
**Author:** [@Suthriel](https://forums.unrealengine.com/u/Suthriel)\ **Replies:** 9\ **Last updated:** [June 17, 2026, 11:54pm UTC](https://forums.unrealengine.com/t/pathtracer-and-niagara-particles-since-when-do-they-work-together/569386 "2026-06-17T23:54:50Z")
Hey, not really a question, more like a nice surprise for me, because i didn´t know, that the Pathtracer (4.27, the UE 5.0 crashed permanently with this test) and Niagara Particles work together and can even illuminate … --- ## [Can you use Path Tracing on MetaHuman Grooms? If so, how?](https://forums.unrealengine.com/t/can-you-use-path-tracing-on-metahuman-grooms-if-so-how/2720854)
**Author:** [@MADMOVIESINC](https://forums.unrealengine.com/u/MADMOVIESINC)\ **Replies:** 0\ **Last updated:** [May 8, 2026, 1:31pm UTC](https://forums.unrealengine.com/t/can-you-use-path-tracing-on-metahuman-grooms-if-so-how/2720854 "2026-05-08T13:31:33Z")
Hello there! I’m trying to render a MetaHuman using Path Tracer in a 5.6 project. The hair is almost not visible at all though in the render. Below is a screenshot of the preview window and a frame that was rendered wit… --- ## [Unreal 5.5 Path Tracer GPU Dumps Abnormally](https://forums.unrealengine.com/t/unreal-5-5-path-tracer-gpu-dumps-abnormally/2694483)
**Author:** [@RB\_Brendan](https://forums.unrealengine.com/u/RB_Brendan)\ **Replies:** 2\ **Last updated:** [April 28, 2026, 5:52pm UTC](https://forums.unrealengine.com/t/unreal-5-5-path-tracer-gpu-dumps-abnormally/2694483 "2026-04-28T17:52:47Z")
I am running into a weird issue when trying to use the path tracer in my Unreal Engine project. What’s odd is that I’ve been able to use the path tracer in the past on this PC and I’m not sure what’s changed since the ti… --- ## [Light Visibility Through Glass Objects/Materials](https://forums.unrealengine.com/t/light-visibility-through-glass-objects-materials/866106)
**Author:** [@EvanHammel](https://forums.unrealengine.com/u/EvanHammel)\ **Replies:** 4\ **Last updated:** [April 20, 2026, 9:22am UTC](https://forums.unrealengine.com/t/light-visibility-through-glass-objects-materials/866106 "2026-04-20T09:22:44Z")
Hi there, I’m using 5.2 Preview 2 to test out what’s new in the world of UE Path Tracing. One thing I still don’t see is the ability to turn off light visibility in refractions. In the example here, I have a skylig… --- ## [Fractured mesh artifact when Path Tracing render](https://forums.unrealengine.com/t/fractured-mesh-artifact-when-path-tracing-render/2228070)
**Author:** [@gaeunee1](https://forums.unrealengine.com/u/gaeunee1)\ **Replies:** 1\ **Last updated:** [April 16, 2026, 4:07am UTC](https://forums.unrealengine.com/t/fractured-mesh-artifact-when-path-tracing-render/2228070 "2026-04-16T04:07:10Z")
hi I have an issue when I render a fractured geometry collection in path tracing (In deferred there’s no problem) When converting a mesh to a Geometry Collection in Fracture Mode, shadow artifacts appear (the issue of… --- ## [Crash on Path Traced render The paging file is too small for this operation to complete](https://forums.unrealengine.com/t/crash-on-path-traced-render-the-paging-file-is-too-small-for-this-operation-to-complete/2693111)
**Author:** [@eco\_bach2](https://forums.unrealengine.com/u/eco_bach2)\ **Replies:** 1\ **Last updated:** [January 19, 2026, 9:51pm UTC](https://forums.unrealengine.com/t/crash-on-path-traced-render-the-paging-file-is-too-small-for-this-operation-to-complete/2693111 "2026-01-19T21:51:52Z")
Using Virtual Textures with a large project (think City Sample). I am constantly crashing with longer (100+) 4k Path Traced frame renders and getting the following error “The paging file is too small for this operation… --- ## [Does path tracer support subsurface profile in substrate materials?](https://forums.unrealengine.com/t/does-path-tracer-support-subsurface-profile-in-substrate-materials/2689447)
**Author:** [@kk13](https://forums.unrealengine.com/u/kk13)\ **Replies:** 1\ **Last updated:** [January 5, 2026, 7:07pm UTC](https://forums.unrealengine.com/t/does-path-tracer-support-subsurface-profile-in-substrate-materials/2689447 "2026-01-05T19:07:07Z")
When I render materials using subsurface profile with normal lighting, everything works fine. However, when I switch to path tracer, the subsurface profile has no effect at all. Is this because path tracer currently does… --- ## [Ugly shadows on Landscape using Path Tracing ](https://forums.unrealengine.com/t/ugly-shadows-on-landscape-using-path-tracing/2688441)
**Author:** [@Jacobian369](https://forums.unrealengine.com/u/Jacobian369)\ **Replies:** 0\ **Last updated:** [December 29, 2025, 3:56pm UTC](https://forums.unrealengine.com/t/ugly-shadows-on-landscape-using-path-tracing/2688441 "2025-12-29T15:56:09Z")
Hello Community, I am working with Landscapes and I got weird sharp shadows on my Landscape. I found an solution for this using the command: “r.RayTracing.NormalBias 50”, using raytraced shadows (Photo 1). This command … --- ## [Why are my Path Tracing renders blurry while my Path Tracing screenshots are clear?](https://forums.unrealengine.com/t/why-are-my-path-tracing-renders-blurry-while-my-path-tracing-screenshots-are-clear/841438)
**Author:** [@EmergencyPoncho](https://forums.unrealengine.com/u/EmergencyPoncho)\ **Replies:** 9\ **Last updated:** [December 10, 2025, 6:39pm UTC](https://forums.unrealengine.com/t/why-are-my-path-tracing-renders-blurry-while-my-path-tracing-screenshots-are-clear/841438 "2025-12-10T18:39:47Z")
Hi there! I’m finishing up a project and creating a final still image. I’m rendering with the Movie Render Que and using Path Tracing. My settings is based on the Still\_Ultra preset and modified it a bit. But when I rend… --- ## [Does Path Tracer support renders with Burn In?](https://forums.unrealengine.com/t/does-path-tracer-support-renders-with-burn-in/642189)
**Author:** [@SupremeOrder](https://forums.unrealengine.com/u/SupremeOrder)\ **Replies:** 2\ **Last updated:** [November 12, 2025, 3:53pm UTC](https://forums.unrealengine.com/t/does-path-tracer-support-renders-with-burn-in/642189 "2025-11-12T15:53:20Z")
The Burn-In works fine when using Deferred Rendering, but it does not show when rendering with Path Tracer (UE 5.0.3). The Movie Pipeline Burn-In is really important for development and staging phases. --- ## [Overexposed caustics or light refraction with Path Tracing](https://forums.unrealengine.com/t/overexposed-caustics-or-light-refraction-with-path-tracing/2673267)
**Author:** [@Creo](https://forums.unrealengine.com/u/Creo)\ **Replies:** 0\ **Last updated:** [November 9, 2025, 4:26pm UTC](https://forums.unrealengine.com/t/overexposed-caustics-or-light-refraction-with-path-tracing/2673267 "2025-11-09T16:26:47Z")
Hi, While using Path Tracer and glass materials I’ve faced with overexposed (or over brightened) caustics from glass. First of all, to create glass materials I used official documentation Here is two room renders with… --- ## [ Path tracing rendering water or semi-transparent objects disappear ](https://forums.unrealengine.com/t/path-tracing-rendering-water-or-semi-transparent-objects-disappear/2667269)
**Author:** [@Anonymous\_f6110ffce6b3a833c4fdd6c56d5fcb73](https://forums.unrealengine.com/u/Anonymous_f6110ffce6b3a833c4fdd6c56d5fcb73)\ **Replies:** 0\ **Last updated:** [October 21, 2025, 2:53pm UTC](https://forums.unrealengine.com/t/path-tracing-rendering-water-or-semi-transparent-objects-disappear/2667269 "2025-10-21T14:53:08Z")
Path tracing rendering water or semi-transparent objects disappear~ Is this a material issue? If I use a path tracing renderer, do I need to change the material ball? Are there any tutorials or examples that clearly ind… --- ## [Foliage issue in path tracing](https://forums.unrealengine.com/t/foliage-issue-in-path-tracing/2651533)
**Author:** [@Nasty1512](https://forums.unrealengine.com/u/Nasty1512)\ **Replies:** 1\ **Last updated:** [September 1, 2025, 9:54pm UTC](https://forums.unrealengine.com/t/foliage-issue-in-path-tracing/2651533 "2025-09-01T21:54:49Z")
How to fix the leaf card in path tracing? Path tracer Lumen --- ## [Pathtracing\_Trees Mask Material Issue](https://forums.unrealengine.com/t/pathtracing-trees-mask-material-issue/2604805)
**Author:** [@DeoVerse](https://forums.unrealengine.com/u/DeoVerse)\ **Replies:** 0\ **Last updated:** [July 15, 2025, 4:25am UTC](https://forums.unrealengine.com/t/pathtracing-trees-mask-material-issue/2604805 "2025-07-15T04:25:37Z")
--- ## [Geometry Collections and Distance-Fields / Ray Tracing](https://forums.unrealengine.com/t/geometry-collections-and-distance-fields-ray-tracing/869546)
**Author:** [@Loux\_xavier](https://forums.unrealengine.com/u/Loux_xavier)\ **Replies:** 12\ **Last updated:** [June 11, 2025, 1:19pm UTC](https://forums.unrealengine.com/t/geometry-collections-and-distance-fields-ray-tracing/869546 "2025-06-11T13:19:43Z")
Good morning, I use the Unreal Engine destruction system. But I have problems with rendering Geometry Collections. Currently it is not possible to generate Distance-Fields for Geometry Collections so rendering with Lum… --- ## [Path Tracer Get Darker Then Lumen](https://forums.unrealengine.com/t/path-tracer-get-darker-then-lumen/2546622)
**Author:** [@kurd\_rehz](https://forums.unrealengine.com/u/kurd_rehz)\ **Replies:** 1\ **Last updated:** [June 8, 2025, 10:15am UTC](https://forums.unrealengine.com/t/path-tracer-get-darker-then-lumen/2546622 "2025-06-08T10:15:12Z")
"Rendering with Path Tracer results in a slightly darker image compared to Lumen as you can see in both images which the one that is in this topic is brighter Which its with lumen and other one which i will put in co… --- ## [Path Tracing Glass Material Black artifacts](https://forums.unrealengine.com/t/path-tracing-glass-material-black-artifacts/2156370)
**Author:** [@Txikimorin](https://forums.unrealengine.com/u/Txikimorin)\ **Replies:** 18\ **Last updated:** [June 4, 2025, 3:00pm UTC](https://forums.unrealengine.com/t/path-tracing-glass-material-black-artifacts/2156370 "2025-06-04T15:00:34Z")
Hi all, I´m here regarding an issue with glass material in Path Tracing. Let me explain my goal first so that you can better understand the issue. I am trying to prepare a Metahuman to be rendered in Path Tracing. M… --- ## [Path Tracing constantly refreshing](https://forums.unrealengine.com/t/path-tracing-constantly-refreshing/785961)
**Author:** [@SupremeOrder](https://forums.unrealengine.com/u/SupremeOrder)\ **Replies:** 2\ **Last updated:** [April 18, 2025, 6:21am UTC](https://forums.unrealengine.com/t/path-tracing-constantly-refreshing/785961 "2025-04-18T06:21:18Z")
Is there any way to stop Path Tracing from constantly refreshing when working with Sequencer? I understand the refresh logic when changing frames, but Path Tracing keeps resetting even If the sequence is paused, it neve… --- ## [Graphics card compatibility Path Tracer Twinmotion 2025](https://forums.unrealengine.com/t/graphics-card-compatibility-path-tracer-twinmotion-2025/2436442)
**Author:** [@Rmzarquitectos](https://forums.unrealengine.com/u/Rmzarquitectos)\ **Replies:** 0\ **Last updated:** [April 2, 2025, 4:56pm UTC](https://forums.unrealengine.com/t/graphics-card-compatibility-path-tracer-twinmotion-2025/2436442 "2025-04-02T16:56:10Z")
HI! I’m trying to use Path tracer with Twinmotion 2025, I was able to use it perfectly fine in Twinmotion 2023 but in 2025 I get a Grayed out button with the message: “The path Tracer is deactivated because DX12 is disa… --- ## [Renders with PathTracing in Unreal Engine 5 (Realism Render)](https://forums.unrealengine.com/t/renders-with-pathtracing-in-unreal-engine-5-realism-render/2403877)
**Author:** [@KaisarR8L](https://forums.unrealengine.com/u/KaisarR8L)\ **Replies:** 3\ **Last updated:** [March 21, 2025, 7:51pm UTC](https://forums.unrealengine.com/t/renders-with-pathtracing-in-unreal-engine-5-realism-render/2403877 "2025-03-21T19:51:27Z")
PathTracing render in Unreal Engine 5 - Vimeo (High resolution) Location Presentation - Youtube (WIP) My experiments with PathTracing and Lumen in Unreal Engine 5 Location on video: Pavilions at VDNH (Exhibit… --- ## [Unreal Engine Archviz-Path Tracing Improvements](https://forums.unrealengine.com/t/unreal-engine-archviz-path-tracing-improvements/2119384)
**Author:** [@N\_DOKY](https://forums.unrealengine.com/u/N_DOKY)\ **Replies:** 11\ **Last updated:** [March 4, 2025, 9:31am UTC](https://forums.unrealengine.com/t/unreal-engine-archviz-path-tracing-improvements/2119384 "2025-03-04T09:31:09Z")
Greeting Fellow UE Experts: I am currently working in a property company that uses Path Tracing in Unreal Engine to render architectural projects. Although we often encounter challenges with using Unreal Engine for prop… --- ## [Problem with rendering of 20th frame in Movie Render Graph (UE5.5.3)](https://forums.unrealengine.com/t/problem-with-rendering-of-20th-frame-in-movie-render-graph-ue5-5-3/2329457)
**Author:** [@kandonede](https://forums.unrealengine.com/u/kandonede)\ **Replies:** 2\ **Last updated:** [February 14, 2025, 8:52am UTC](https://forums.unrealengine.com/t/problem-with-rendering-of-20th-frame-in-movie-render-graph-ue5-5-3/2329457 "2025-02-14T08:52:56Z")
Hello, colleagues! Encountered a problem with rendering in Movie Render Graph: starting from the 15th frame, the rendering time increases by 2-3 times, and on the 20th frame the process is almost stopped (formally it co… --- ## [Instances Disappearing in the Path-Traced View](https://forums.unrealengine.com/t/instances-disappearing-in-the-path-traced-view/692563)
**Author:** [@REM\_Visuals](https://forums.unrealengine.com/u/REM_Visuals)\ **Replies:** 2\ **Last updated:** [February 7, 2025, 8:52pm UTC](https://forums.unrealengine.com/t/instances-disappearing-in-the-path-traced-view/692563 "2025-02-07T20:52:21Z")
when i turn on path tracing, the instances dissapear, i tried the console command in the manual " r.RayTracing.Geometry.InstancedStaticMeshes.Culling" (Path Tracer in Unreal Engine | Unreal Engine 5.1 Documentation) but… --- ## [\[Bug\] Light Uniform Sampling in PathTracing](https://forums.unrealengine.com/t/bug-light-uniform-sampling-in-pathtracing/2296717)
**Author:** [@user\_fdc286c4ebdd83f4e53256a83e5e32a87339769f65057e051d1ab5](https://forums.unrealengine.com/u/user_fdc286c4ebdd83f4e53256a83e5e32a87339769f65057e051d1ab5)\ **Replies:** 0\ **Last updated:** [January 22, 2025, 8:24am UTC](https://forums.unrealengine.com/t/bug-light-uniform-sampling-in-pathtracing/2296717 "2025-01-22T08:24:57Z")
https://github.com/EpicGames/UnrealEngine/blob/release/Engine/Shaders/Private/PathTracing/Light/PathTracingLightSampling.ush#L128 For the function SelectLight which pick a lights by uniform samping When UNIFORM\_LIGHT\_SE… --- ## [MRQ: Strange 3-Pixel-Glitches on 8bit formats caused by Tone Curve?](https://forums.unrealengine.com/t/mrq-strange-3-pixel-glitches-on-8bit-formats-caused-by-tone-curve/2005135)
**Author:** [@seersense](https://forums.unrealengine.com/u/seersense)\ **Replies:** 9\ **Last updated:** [January 20, 2025, 9:40am UTC](https://forums.unrealengine.com/t/mrq-strange-3-pixel-glitches-on-8bit-formats-caused-by-tone-curve/2005135 "2025-01-20T09:40:01Z")
Usually I render EXR with ACEScg color output. However for a certain workflow where i have to render many different things on a perfect 100% white Background. I found I could leave out any Post-Production and save a bunc… --- ## [Renderings have black border pixel row or column and shifts image by 1 Pixel](https://forums.unrealengine.com/t/renderings-have-black-border-pixel-row-or-column-and-shifts-image-by-1-pixel/2004870)
**Author:** [@seersense](https://forums.unrealengine.com/u/seersense)\ **Replies:** 8\ **Last updated:** [January 20, 2025, 9:39am UTC](https://forums.unrealengine.com/t/renderings-have-black-border-pixel-row-or-column-and-shifts-image-by-1-pixel/2004870 "2025-01-20T09:39:06Z")
When Rendering the entire image gets shifted in either horizontal or vertical direction by a single pixel, leaving a row or column of black pixels at one border. Very annoying, especially for compositing. First I thought… --- ## [Hair and translucents not visible in Path Tracing (5.5) Any workaround?](https://forums.unrealengine.com/t/hair-and-translucents-not-visible-in-path-tracing-5-5-any-workaround/2246413)
**Author:** [@Miguel1900](https://forums.unrealengine.com/u/Miguel1900)\ **Replies:** 0\ **Last updated:** [December 27, 2024, 10:57pm UTC](https://forums.unrealengine.com/t/hair-and-translucents-not-visible-in-path-tracing-5-5-any-workaround/2246413 "2024-12-27T22:57:55Z")
That’s it. Translucents are invisible when enabling Path Tracing (while they were working fine in 5.3 and 5.4). Hair, as is translucent too, will be invisible too. Only Water Layer is visible. Do you know any workaround… [Next page](https://forums.unrealengine.com/tag/path-tracing/11338.md?match_all_tags=true&page=1&tags%5B%5D=Path-Tracing)