FAQ

Getting Started

Unity recommended version.

Predict Unity has been developed on Unity 2020 LTS (https://unity3d.com/fr/unity/qa/lts-releases?version=2020.3). 

It is recommended to use this version. You may use a later version of Unity but be aware that we did not test every Predict Unity feature on later versions.

I get the following error, what can I do ?
ExecutionEngineException: String conversion error: Illegal byte sequence encounted in the input.

There might be a problem with your system locale. Make sure you enabled the UTF-8 option the the region settings. See the Predict Engine set up section for more details.

System requirements to use Predict Engine.

OS: Predict Engine can be installed on Windows (10 or higher) or Linux (kernel >=3.18). 

GPU: Predict Engine requires at least a Nvidia Pascal GPU (GeForce GTX 1050 TI 4go), but we recommend using a Turing card (RTX 2070 8go) or above. 

Drivers: The Nvidia video driver version should be 495.89.0  or higher and the Nvidia card compute capability should be of 6.0 or higher. See this link for details on which driver is currently installed: https://nvidia.custhelp.com/app/answers/detail/a_id/2039/~/how-do-i-determine-which-nvidia-display-driver-version-is-currently-installed.

Unity HDRP pipeline support with Predict Unity.

The recommended HDRP package version is 10.6.0.

My license should be working but it is considered as invalid. I get the "license successfully activated" message but the license is then displayed as invalid.

UVR licenses require the system to be synchronized with the Cryptlex time system. If your machine is more than 5 minutes apart from the license server, the license will be considered as invalid. Open the Engine setup section for more details.

Project Settings

Using the HDRP pipeline, the engine overlay doesn't appear in front of the Unity render. How come ?

When using the HDRP pipeline, you must set the UVR post process by following the next steps:

I get the following error, what should I do ?
"The type or namespace name 'InputSystem' does not exist in the namespace 'UnityEngine' (are you missing an assembly reference?)"

Unity's new input system require a specific package to be loaded in the project. You can load this package by opening the package manager window (menu "Window/Package Manager"), and installing the "Input System" package from the Unity registry. 

Scene Building

My output image is very dark or very light, it doesn't seem natural, what should I do ?

This can be due to a bad gamma correction. See the Post Pipeline section for more details.

Materials

Can I use Unity standard materials or custom shaders in my Predict Engine scenes ?

Yes. Without additional settings, an equivalent RGB material will be loaded in Predict Engine. See the Material section for more details on how to define the Predict Matter spectral and polarized material.

How can I choose whether materials are double sided or not ?

You can define the "IsDoubleSided" property of all the materials in the scene in the UVR preferences, in the section Default Settings. See the Preferences section for more details.

How can I create a material with a coating ?

Materials with coatings are defined using an "Interface" material. See the interface materials section for more details.

How can I define a complex interface between two materials (liquid in a glass for instance) ?

Complex interface materials are defined using an "Interface" material. See the interface materials section for more details.

Lights

Why does my area light don't seem to emit uniformly across its surface ?

This can be induced by a bad definition of the reference frame of the area light. See the Area light geometries section for more details.

Geometries

Geometry formats supported by Predict Unity ?

All the formats that are supported in Unity.

Dimensions of the default Unity geometries ?

The geometries that can be instantiated via the menu “GameObject/3D Object/*” are default Unity geometries. Their dimensions (given in the scene scale unit) are the following :

I defined a very thin geometry in my scene. Why does it not appear in Predict Engine ?

This can be induced by a bad definition of the epsilons of the scene. See the Scene section for more details.

Why do I see black triangles and polygons in my scene ?

This can be induced by a bad definition of the epsilons of the scene. See the Scene section for more details.

Why do the shadows in my scene are crenelated ?

This can be induced by a bad definition of the epsilons of the scene. See the Scene section for more details.

I can't find a good definition for the epsilons in my scene. What should I do ?

If you can't find a good epsilon to get rid of all the artefacts in your scene, or if you see in the scene artefacts for an epsilon that is too small and too high at the same time, it can be caused by a bad placement of the geometries in their local framework.
See the Scene section for more details.

Some of my geometries seem to be missing UV coordinates but I don't know  which ones, how can I find them ?

You can use the menu "PredictSuite/Tools/Select geometries without UV coordinates" to select all concerned GameObjects in the scene.

Interface

The UI elements are not visible when I use the Game view (loading arrows, false color scale,...). What should I do ?

Make sure the camera scale is {1;1;1}. The scale of the camera is defined on its Transform and can be affected by parent Transforms.
If the camera scale is higher than 1, the UI elements can be displayed outside the screen space.

Upgrades

How can I upgrade my version of Predict Unity ?

See the Upgrade section for more details.