From 412cd9b9bfb77d91a0b6e9a7bc9da7c5a14ec628 Mon Sep 17 00:00:00 2001 From: Lewis Jordan Date: Fri, 30 Apr 2021 11:21:58 +0100 Subject: [PATCH 1/2] Added ray tracing light culling section and moved a couple of things around --- .../Ray-Tracing-Getting-Started.md | 32 ++++++++++--------- 1 file changed, 17 insertions(+), 15 deletions(-) diff --git a/com.unity.render-pipelines.high-definition/Documentation~/Ray-Tracing-Getting-Started.md b/com.unity.render-pipelines.high-definition/Documentation~/Ray-Tracing-Getting-Started.md index b58ef3c301d..2bd3e685fd2 100644 --- a/com.unity.render-pipelines.high-definition/Documentation~/Ray-Tracing-Getting-Started.md +++ b/com.unity.render-pipelines.high-definition/Documentation~/Ray-Tracing-Getting-Started.md @@ -186,20 +186,6 @@ To check whether it is possible to use ray tracing in a Scene, HDRP includes a m 1. Click **Edit > Rendering > Check Scene Content for HDRP Ray Tracing**. 2. In the Console window (menu: **Window > General > Console**), check if there are any warnings. - - -# Ray tracing and Meshes - -HDRP changes how it handles Meshes in your scene when you integrate a ray traced effect into your project. - -When you enable ray tracing, HDRP automatically creates a ray tracing acceleration structure. This structure allows Unity to calculate ray tracing for Meshes in your scene efficiently in real time. - -As a result, ray tracing can change how some Meshes appear in your scene in the following ways: - -- If your Mesh has a Material assigned that does not have the HDRenderPipeline tag, HDRP does not add it to the acceleration structure and does not apply any ray traced effects to the mesh as a result. -- If your Mesh has a Decal Material assigned, HDRP does not add it to the acceleration structure and the Mesh does not appear in your scene. -- If a Mesh has a combination of Materials that are single and double-sided, HDRP flags all Materials you have assigned to this mesh as double-sided. - ## Ray tracing effects overview @@ -214,8 +200,24 @@ HDRP uses ray tracing to replace some of its screen space effects, shadowing tec - [Recursive Ray Tracing](Ray-Tracing-Recursive-Rendering.md) replaces the rendering pipeline for Meshes. Meshes that use this feature cast refraction and reflection rays recursively. - [Ray-Traced Subsurface Scattering](Ray-Traced-Subsurface-Scattering.md) replaces [subsurface scattering](Subsurface-Scattering.md) with a more accurate, ray-traced, subsurface scattering technique that can use off screen data. -## Ray tracing mode + + +## Ray tracing and Meshes + +HDRP changes how it handles Meshes in your scene when you integrate a ray traced effect into your project. + +When you enable ray tracing, HDRP automatically creates a ray tracing acceleration structure. This structure allows Unity to calculate ray tracing for Meshes in your scene efficiently in real time. + +As a result, ray tracing can change how some Meshes appear in your scene in the following ways: +- If your Mesh has a Material assigned that does not have the HDRenderPipeline tag, HDRP does not add it to the acceleration structure and does not apply any ray traced effects to the mesh as a result. +- If your Mesh has a Decal Material assigned, HDRP does not add it to the acceleration structure and the Mesh does not appear in your scene. +- If a Mesh has a combination of Materials that are single and double-sided, HDRP flags all Materials you have assigned to this mesh as double-sided. + +## Ray tracing light culling +Ray tracing requires HDRP to cull lights differently to how it culls lights for rasterization. With rasterization, only lights that affect the current frustum matter. Since ray tracing uses off-screen data for effects such as reflection, HDRP needs to take into account lights that affect off screen geometry. For this reason, HDRP defines a range around the camera where it gathers light visible in reflections. To control this range, use the [Light Cluster](Ray-Tracing-Light-Cluster.md) Volume override. It is important to set a range that accurately represents the environment. A higher range makes HDRP include lights further away, but it also increases the resource intensity of light culling for ray tracing. + +## Ray tracing mode HDRP includes two ray tracing modes that define how it evaluates certain ray-traced effects. The modes are: * **Performance**: This mode targets real-time applications. If you select this mode, ray-traced effects include presets that you can change to balance performance with quality. From 0639bcb0458604e1034bca09b964fa8ba63bbd7e Mon Sep 17 00:00:00 2001 From: sebastienlagarde Date: Fri, 30 Apr 2021 13:19:13 +0200 Subject: [PATCH 2/2] Update Ray-Tracing-Getting-Started.md --- .../Documentation~/Ray-Tracing-Getting-Started.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/com.unity.render-pipelines.high-definition/Documentation~/Ray-Tracing-Getting-Started.md b/com.unity.render-pipelines.high-definition/Documentation~/Ray-Tracing-Getting-Started.md index 2bd3e685fd2..7994aff4e47 100644 --- a/com.unity.render-pipelines.high-definition/Documentation~/Ray-Tracing-Getting-Started.md +++ b/com.unity.render-pipelines.high-definition/Documentation~/Ray-Tracing-Getting-Started.md @@ -215,7 +215,7 @@ As a result, ray tracing can change how some Meshes appear in your scene in the - If a Mesh has a combination of Materials that are single and double-sided, HDRP flags all Materials you have assigned to this mesh as double-sided. ## Ray tracing light culling -Ray tracing requires HDRP to cull lights differently to how it culls lights for rasterization. With rasterization, only lights that affect the current frustum matter. Since ray tracing uses off-screen data for effects such as reflection, HDRP needs to take into account lights that affect off screen geometry. For this reason, HDRP defines a range around the camera where it gathers light visible in reflections. To control this range, use the [Light Cluster](Ray-Tracing-Light-Cluster.md) Volume override. It is important to set a range that accurately represents the environment. A higher range makes HDRP include lights further away, but it also increases the resource intensity of light culling for ray tracing. +Ray tracing requires HDRP to cull lights differently to how it culls lights for rasterization. With rasterization, only lights that affect the current frustum matter. Since ray tracing uses off-screen data for effects such as reflection, HDRP needs to take into account lights that affect off screen geometry. For this reason, HDRP defines a range around the camera where it gathers light. To control this range, use the [Light Cluster](Ray-Tracing-Light-Cluster.md) Volume override. It is important to set a range that accurately represents the environment scale. A higher range makes HDRP include lights further away, but it also increases the resource intensity of light culling for ray tracing. ## Ray tracing mode HDRP includes two ray tracing modes that define how it evaluates certain ray-traced effects. The modes are: