Upgrading HDRP from Unity 2019.2 to Unity 2019.3

In the High Definition Render Pipeline (HDRP), some features work differently between major versions of Unity. This document helps you upgrade HDRP from Unity 2019.2 to 2019.3.

New Scene

New Scene system in HDRP rely on a prefab in your project. It also depend on default settings set for the Volumes. If you already have configured one with the Wizard, you need to update it regarding the Default Volume Profile Asset (in Edit > Project Settings > HDRP Default Settings).

If you use default prefab (the one created by the wizard) and rely on default Default Volume Profile Asset, then your prefab will not be sync anymore with the default volume profile and you must update it.

The easiest way is to ask the Wizard to recreate a new one:

  1. Open the Wizard (Window > Render Pipeline > HD Render Pipeline Wizard)
  2. Remove the prefab set in Default Scene Prefab.
  3. [Optional] Keep a copy of your previous prefab if it have been customized to not lost your version. To do so, just rename the prefab. It will prevent to be overridden.
  4. Look at the Configuration Checking below for the line Default Scene Prefab and click on the Fix button.
  5. [Optional] Report your custom change in the new created prefab.

Then repeat this for Default DXR Scene Prefab if you were also using DXR.

New Scene system in HDRP rely on a prefab in your project. If you have already configured one with the Wizard, you need to update it.

Procedural Sky

The Procedural Sky override is deprecated in Unity 2019.3. If your Project uses a procedural sky, you either need to install the override from the samples or switch to the new physically based sky.

To install the Procedural Sky override into a 2019.3 Project:

  1. Open your Project in the Unity Editor.
  2. Open the Package Manager (Window > Package Manager) and click on High Definition RP
  3. In the Samples section, click on the Import in project button for the Procedural Sky entry. If you have a Scene open that uses the Procedural Sky, the sky re-appears, but its settings are reset to the default values.
  4. To recover your sky settings, you must quit Unity without saving and then re-open your Project.

The last step is important because, if you haven't installed the sample and load a Scene that uses a Procedural Sky, then the Procedural Sky data in the Volume is lost. Unity does not serialize this so you can close and re-open Unity to recover your settings.

Sky Intensity Mode

In HDRP for 2019.3, the way sky intensity is handled has been changed. Before the change, there were two parameters: Exposure and Multiplier that we both applied to change the sky intensity. Now, there is a new combo box for users to chose between one or the other. An update script is provided in Edit > Render Pipeline > Upgrade Sky Intensity Mode to upgrade the existing sky components.

Fog

HDRP has deprecated the Linear Fog, Exponential Fog, Volumetric Fog, and Volumetric Fog Quality overrides in 2019.3 and replaced them with a single Fog override. This override acts as an exponential fog with a height component by default and allows you to add additional volumetric fog. To automatically update old fog overrides to the new system, select Edit > Render Pipeline > Upgrade Fog Volume Components. Note that it can not safely convert all cases so you may need to upgrade some manually.

Shadow Maps

Before Unity 2019.3, each Light in HDRP exposed several options for the shadow map bias. From 2019.3, HDRP has replaced every option, except for Normal Bias, with Slope-Scale Depth Bias. Introducing this property makes the shadow map bias setup fairly different to what it was. This means that, if the default values lead to unexpected results, you may need a new setup for the bias on each Light.

Also, before Unity 2019.3, PCSS had a different parametrization. Since 2019.3, the shadow softness is controlled by angular diameter on directional lights and by shape radius for point and spot lights. To convert the previous shadow softness to a shape radius, an approximate function is: 0.333 * oldSoftness * (shadowResolution / 512). Moreover, the Minimum filter size option is now called Minimum Blur Intensity; this is functionally equivalent but simply remaps the previous range [0 ... 0.0001] to [0 ... 1].

Lights

From Unity 2019.3, the available Light types are Directional, Point, Spot, and Area so that they match the types in the Built-in Renderer. You can select the shape of Area lights (from Rectangle, Tube, and Disc) after your select Area as your Light type.

Area Lights

Before Unity 2019.3, HDRP synchronized the width and height of an area Light's Emissive Mesh with the localScale of its Transform. From Unity 2019.3, HDRP uses the lossyScale to make the Emissive Mesh account for the scale of the parent Transforms. This means that you must resize every area Light in your Unity Project according to the scale of its parent.

Before Unity 2019.3, we stored cookies of Spot, Area and directional lights and planars into texture arrays. Due to the usage of these arrays, we were limited to use the same size for every element in one array. For cookie textures, a convertion code ensured that if a texture size wasn't exatcly the same as the size of the texture array (defined in the HDRP asset), then it was scaled to fit the size of the array.
Now that we're using an atlas we don't have this limitation anymore. It means that the cookie size you were using might differ now that we use the real size of the texture and could result in more sharp / pixelated cokies if your texture were too big or too small. If you encounter this kind of issue, we recommend fixing the images directly. For Planar Reflection Probes it also means that you can use different resolution per probe.

You may also encounter this error in the console: No more space in the 2D Cookie Texture Atlas. To solve this issue, increase the resolution of the cookie atlas in the HDRP settings. This means that there is no space left in the Cookie atlas because there are too many of them in the view or the cookie textures are too big. To solve this issue you can either lower the resolution of the cookie textures or increase the atlas resolution in the HDRP settings.

Max Smoothness, Emission Radius, Bake Shadows Radius and Bake Shadows Angle

Before Unity 2019.3, Max Smoothness, Emission Radius, and Bake Shadows Radius were separate controls for Point and Spot Lights. From Unity 2019.3, the UI displays a single property, called Radius that controls all of the properties mentioned above. Also, Max Smoothness, Angular Diameter, and Bake Shadows Angle were separate controls for Directional Lights. The UI now displays a single property, called Angular Diameter, that controls all the mentioned above.

When upgrading, a slight shift of highlight shape or shadow penumbra size can occur. This happens if you set the original properties to values that do not match what the automatic conversion from "Radius" or "Angular Diameter" results in.

Realtime GI Enlighten

From Unity 2019.3, HDRP no longer supports realtime GI for new Projects. However, HDRP still supports realtime GI for Projects that you previously created for 2019.3 LTS only.

Custom Shaders

Unity 2019.3 introduces a change to Reflection Probes which allows you to compress the range that Unity uses when rendering the probe's content. This comes with a small change to the Shader framework, the function SampleEnv() now requires an additional parameter, being the factor to apply to the probe data to compensate the range compression done at probe rendering time. This value is in the data structure EnvLightData under the name of rangeCompressionFactorCompensation.

HDRP Asset and Default Settings

From Unity 2019.3, a lot of HDRP’s settings have moved. Specifically, most of the information that was previously in the HDRP Asset is now mirrored in Project Settings.
There are two separate categories:

  • Default Settings (Project Settings > HDRP Default Settings), where you can serve up default Frame Andy Volume Settings.
  • Quality Settings (Project Settings > Quality > HDRP), where you can manage settings for multiple Render Pipeline Assets.

From Unity 2019.3, Baking sky / Static lighting Sky Components are deprecated. Settings are now in (Lighting Window > Environment lighting) and use a Volume Profile Asset and a drop-down to select the sky to use for baking. You can remove the Static Lighting Sky component from your Scenes.

Shorcut for volume settings

From Unity 2019.3, there is no Render Settings shorcut in the context menu to create pre-set Volume settings. HDRP uses Default Settings (Project Settings > HDRP Default Settings) instead. HDRP now includes shortcuts for local Volumes of different shapes to ease the process of setting up your Volumes. In addition, HDRP also includes a shortcut which creates a Volume with Sky and Fog overrides as this is a commonly used Volume type.

HDRP Configuration Package

From Unity 2019.3, HDRP has an additional small package as a dependency. This is the HDRP-Config package. You can change properties in this package to disable or tweak features that you cannot control dynamically in HDRP’s UI. Currently, this include:

  • Selecting the Shadow Filtering quality when in Deferred Mode.
  • Camera Relative Rendering.
  • Raytracing.
  • XR Maximum views.
  • Area Lights.

Material Upgrader

When you upgrade your High Definition RP package, Unity now upgrades each of your Materials. This means adds a version number the first time it happens so, if a HDRP Shader change occurs, Unity is able to fix your Material so that it still works correctly with the new changes.

To do this, Unity opens a prompt when you begin the upgrade, asking if you want to save your Project. It keeps attempting to upgrade old files until you agree to save your Project.

Missing Script for GameObject SceneIDMap

When you enter Play Mode in a Scene with baked Probes authored prior to 2019.3, you may encounter a warning about a missing Script for a GameObject named SceneIDMap. To fix this, load the Scene in the Unity Editor and select Edit > Render Pipeline > Fix Warning 'referenced script in (Game Object 'SceneIDMap') is missing' in loaded scenes.

Light Intensity and Sky Exposure versus HDRP Default Settings.

By default, HDRP uses physically correct intensities for Lights. Because of this, the exposure of the default HDRI sky present in HDRP is set to 11 to match a Directional Light intensity of 10000. For reference, you can find similar values in the template Project. When the HDRP Wizard has been set up correctly, if you create a new Scene, Unity automatically creates GameObjects with the correct intensities so that everything is coherent. However, if the HDRP Wizard is not set up correctly, or if you create Directional Lights from scratch, the intensity is not physically correct. The consequence is that the Light does not match the default sky exposure and thus, any GameObject in the Scene looks black because of the automatic exposure compensating for the overly bright sky. To avoid this, make sure that you use coherent values for light intensity compared to the current sky exposure.

Iridescence color space

Previously, HDRP used the wrong color space to calculate iridescence. From 2019.3, HDRP uses the correct color space. This results in a more vibrant / saturated color when you use the iridescence effect.