# The High Definition Render Pipeline Asset
The High Definition Render Pipeline (HDRP) Asset controls the global rendering settings of your Project and creates an instance of the render pipeline.
Unity only allocates memory and builds shader variants for features you enable in the HDRP Asset. This means that you can disable features your project does not use to save memory. Since certain features require shader variants or other resources when Unity builds your project, you can only enable and disable features at edit time. However, it is possible to toggle the rendering of particular features at runtime, just not using the HDRP Asset. Instead, [Frame-Settings](Frame-Settings.md) control the features that cameras in the scene render. Frame Settings can only toggle features that are enabled in the HDRP Asset; they cannot enable features that are disabled.
## Rendering
| **Property** | **Description** |
|------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| **Color Buffer Format** | The format of the color buffer that HDRP will use for rendering, using R16G16B16A16 instead of R11G11B10 will double the memory usage but help you to avoid banding. R16G16B16A16 is also required for [Alpha-Output](Alpha-Output.md). |
| **Lit Shader Mode** | Use the drop-down to choose which mode HDRP uses for the [Lit Shader](lit-material.md).
• **Forward Only**: forces HDRP to only use forward rendering for Lit Shaders.
• **Deferred Only**: forces HDRP to use deferred rendering for Lit Shaders (HDRP still renders advanced Materials using forward rendering).
• **Both**: allows the Camera to use deferred and forward rendering.
Select **Both** to allow you to switch between forward and deferred rendering for Lit Shaders at runtime per Camera. Selecting a specific mode reduces build time and Shader memory because HDRP requires less Shader variants, but it is not possible to switch from one mode to the other at runtime. |
| **- Multisample Anti-aliasing Quality** | Use the drop-down to set the number of samples HDRP uses for multisample anti-aliasing (MSAA). The larger the sample count, the better the quality. Select **None** to disable MSAA.
This property is only visible when **Lit Shader Mode** is set to **Forward Only** or **Both**. |
| **Motion Vectors** | Enable the checkbox to make HDRP support motion vectors. HDRP uses motion vectors for effects like screen space reflection (SSR) and motion blur. When disabled, motion blur has no effect and HDRP calculates SSR with lower quality. |
| **Runtime Debug Display** | Enable the checkbox to make HDRP able to use debug modes from the [Rendering Debugger](use-the-rendering-debugger.md) at runtime. Disable the checkbox to reduce build time and shader memory. This disables the following debug modes: All material property debug modes except GBuffer debug, the various property override options, and all the lighting debug modes. |
| **Runtime AOV API** | Enable the checkbox to make HDRP able to use the AOV API (rendering of material properties and lighting modes) at runtime. Disable this checkbox to reduce build time and shader memory. This disables the following AOV modes: All material properties and lighting modes. | |
| **Terrain Hole** | Enable the checkbox to make HDRP support [Terrain Holes](https://docs.unity3d.com/2019.3/Documentation/Manual/terrain-PaintHoles.html). If you do not enable this, Terrain Holes are not visible in your Scene. |
| **Transparent Backface** | Enable the checkbox to make HDRP support transparent back-face render passes. If your Unity Project does not need to make a transparent back-face pass, disable this checkbox to reduce build time. |
| **Transparent Depth Prepass** | Enable the checkbox to make HDRP support transparent depth render prepasses. If your Unity Project does not need to make a transparent depth prepass, disable this checkbox to reduce build time . |
| **Transparent Depth Postpass** | Enable the checkbox to make HDRP support transparent depth render postpasses. If your Unity Project does not make use of a transparent depth postpass. Uncheck this checkbox to reduce build time . |
| **Custom Pass** | Enable the checkbox to make HDRP support custom passes. If your Unity Project does not make use [Custom Passes](Custom-Pass.md), Uncheck this checkbox to save memory . |
| - **Custom Buffer Format** | Specify the texture format for the custom buffer. If you experience banding issues due to your custom passes, you can change it to either `R11G11B10` if you don't need alpha or `R16G16B16A16`. |
| **Realtime Raytracing (Preview)** | Enable the checkbox to enable HDRP realtime ray tracing (Preview). It requires to have ray tracing compatible hardware. For more information, please refer to the [Ray Tracing Getting Started](Ray-Tracing-Getting-Started.md) page. |
| **Visual Effects Ray Tracing (Preview)** | Enable the checkbox to make HDRP support ray tracing with Visual Effects. **Realtime Raytracing (Preview)** must be enabled. |
| **Supported Ray Tracing Mode (Preview)** | Select the supported modes for ray tracing effects (Performance, Quality or Both). For more information, see the [Ray Tracing Getting Started](Ray-Tracing-Getting-Started.md) page. |
| - **LOD Bias** | Set the value that Cameras use to calculate their LOD bias. The Camera uses this value differently depending on the **LOD Bias Mode** you select. |
| - **Maximum LOD Level** | Set the value that Cameras use to calculate their maximum level of detail. The Camera uses this value differently depending on the **Maximum LOD Level Mode** you select. |
### Decals
These settings control the draw distance and resolution of the decals atlas that HDRP uses when it renders decals projected onto transparent surfaces.
| **Property** | **Description** |
| -------------------------------------------- | ------------------------------------------------------------ |
| **Enable** | Enable the checkbox to make HDRP support decals in your Unity Project. |
| **- Draw Distance** | The maximum distance from the Camera at which Unity draws Decals. |
| **- Atlas Width** | The Decal Atlas width. This atlas stores all decals that project onto transparent surfaces. |
| **- Atlas Height** | The Decal Atlas height. This atlas stores all decals that project onto transparent surfaces. |
| ***- Transparent Texture Resolution Tiers*** | Set the resolution that transparent textures take up within the decal atlas. The same resolution is used for all textures of a material (base color, normal, mask). |
| **- Low** | Set the transparent texture resolution to this quality. DecalProjectors with their **Transparent Texture Resolution** set to **Low** use this resolution for their textures in the decal atlas. |
| **- Medium** | Set the transparent texture resolution to this quality. DecalProjectors with their **Transparent Texture Resolution** set to **Medium** use this resolution for their textures in the decal atlas. |
| **- High** | Set the transparent texture resolution to this quality. DecalProjectors with their **Transparent Texture Resolution** set to **High** use this resolution for their textures in the decal atlas. |
| **- Metal and Ambient Occlusion properties** | Enable the checkbox to allow decals to affect metallic and ambient occlusion Material properties. Enabling this feature has a performance impact. |
| **- Maximum Clustered Decals on Screen** | The maximum number of clustered decals that can affect transparent GameObjects on screen. Clustered decals refer to a list of decals that HDRP uses when it renders transparent GameObjects. |
| **- Layers** | Enable the checkbox to allow decals to only affect specific layers.|
### Dynamic Resolution
| **Property** | **Description** |
| ------------------------------------------- | ------------------------------------------------------------ |
| **Enable** | Enable the checkbox to make HDRP support dynamic resolution in your Unity Project. |
| **- Enable DLSS** | Enable the checkbox to make HDRP support NVIDIA Deep Learning Super Sampling (DLSS).
This property only appears if you enable the NVIDIA package (com.unity.modules.nvidia) in your Unity project. |
| **-- Mode** | Use the drop-down to select which performance mode DLSS operates on. The options are:
• **Balanced**: - Balances performance with quality.
• **MaxPerf**: - Fast performance, lower quality.
• **MaxQuality**: - High quality, lower performance.
• **UltraPerformance**: - Fastest performance, lowest quality. |
| **-- Injection Point** | Use the drop-down to select at which point DLSS runs in the rendering pipeline:
• **Before Post**: - DLSS runs when all post processing effects are at full resolution.
• **After Depth Of Field**: - Depth of field runs at a low resolution and DLSS upscales everything in the next rendering step. All other post processing effects run at full resolution.
• **After Post Process**: - DLSS runs at the end of the pipeline when all post process are at low resolution.
• |
| **-- Use Optimal Settings** | Enable the checkbox to make DLSS control the Sharpness and Screen Percentage automatically. |
| **-- Sharpness** | Controls how the DLSS upsampler renders edges on the image. More sharpness usually means more contrast and a clearer image but can increase flickering and fireflies. Unity ignores this property if you enable **Use Optimal Settings**. |
| **- Dynamic Resolution Type** | Use the drop-down to select the type of dynamic resolution HDRP uses:
• **Software**: This option allocates render targets to accommodate the maximum resolution possible, then rescales the viewport accordingly. This allows the viewport to render at varying resolutions.
• **Hardware**: This option treats the render targets, up until the back buffer, as if they are all the scaled size. This means HDRP clears the render targets faster. |
| **- Upscale Filter** | Use the drop-down to select the filter that HDRP uses for upscaling (unless overridden by user via script). The options are:
• **Catmull-Rom**: A bicubic upsample with 4 taps.
• **Contrast Adaptive Sharpen**: An ultra sharp upsample. This option is not meant for screen percentages less than 50% and still sharpens when you set the screen percentage to 100%. It uses **FidelityFX (CAS) AMD™**.
• **FidelityFX Super Resolution 1.0 AMD™**: A spatial super-resolution technology that leverages cutting-edge algorithms to produce impressive upscaling quality at very fast performance.
• **TAA Upscale**: A temporal anti-aliasing upscaler that uses information from previous frames to produce high-quality visuals.
• **Scalable Temporal Post-Processing (STP)**: A low-overhead spatio-temporal anti-aliasing upscaler that attempts to produce sharp visuals at scaling factors as low as 50%. |
| **- Use Mip Bias** | Apply a negative bias on the texture samplers of deferred, opaque and transparent passes. This improves detail on textures but increases the texture fetching cost. Cost varies per platform. |
| **- Minimum Screen Percentage** | The minimum screen percentage that dynamic resolution can reach. |
| **- Maximum Screen Percentage** | The maximum screen percentage that dynamic resolution can reach. This value must be higher than the **Min Screen Percentage**. |
| **- Force Screen Percentage** | Enable the checkbox to force HDRP to use a specific screen percentage for dynamic resolution. This feature is useful for debugging dynamic resolution. |
| **- Forced Screen Percentage** | The specific screen percentage that HDRP uses for dynamic resolution. This property is only visible when you enable the **Force Screen Percentage**.. |
| **- Low Res Transparency Min Threshold** | The minimum percentage threshold allowed to clamp low resolution transparency. When the resolution percentage falls below this threshold, HDRP will clamp the low resolution to this percentage. |
| **- Ray Tracing Half Resolution Threshold** | The minimum percentage threshold allowed to render ray tracing effects at half resolution. When the resolution percentage falls below this threshold, HDRP will render ray tracing effects at full resolution. |
## Compute Thickness
| **Property** | **Description** |
| -------------- | ------------------------------------------------------------ |
| **Enable** | Enable the checkbox to sample the thickness of GameObjects to use in a shader graph material. For more information, refer to [Sample and use material thickness](Compute-Thickness.md). |
| **Resolution** | Set the resolution of a material’s thickness:
•**Quarter**: Renders the thickness at quarter the current screen resolution.
•**Half**: Renders the thickness at half the current screen resolution. This resolution is the best balance of detail and performance.
•**Full**: Renders the thickness at full screen resolution. |
| **Layer Mask** | Select one or more layers to compute the thickness of. |
## Lighting
| **Property** | **Description** |
| ------------------------------------ | ------------------------------------------------------------ |
| **Screen Space Ambient Occlusion** | Enable the checkbox to make HDRP support screen space ambient occlusion (SSAO). SSAO is a technique for approximating ambient occlusion efficiently in real time. |
| **Screen Space Global Illumination** | Enable the checkbox to make HDRP support screen space global illumination (SSGI). SSGI is a technique for approximating global illumination efficiently in real time. |
| **Volumetrics** | Enable the checkbox to make HDRP support volumetrics. This allows you to use **Volumetric Fog** for the **Fog Type** in the [Visual Environment](visual-environment-volume-override-reference.md). |
| **Light Layers** | Enable the checkbox to make HDRP support Light Layers. You can assign a Layer to a Light which then only lights up Mesh Renderers or Terrains with a matching rendering Layer. |
| **Rendering Layer Mask Buffer** | Enable the checkbox to make HDRP write the Rendering Layer Mask of GameObjects in a fullscreen buffer target. This comes with a performance and memory cost.
The [HD Sample Buffer node](https://docs.unity3d.com/Packages/com.unity.shadergraphlatest?subfolder=/manual/HD-Sample-Buffer-Node.html) in ShaderGraph can sample this target. |
### Light Probe Lighting
Use these settings in the **Quality** > **HDRP** menu to configure [Adaptive Probe Volumes](probevolumes.md).
| **Property** | **Sub-property** | **Description** |
|-|-|-|
| **Light Probe System** ||