Developer can modify the value of RenderTexture, which depends on the scene's needs, the default value is 1 (Recommended). The value less, the resolution will be lower, but FPS will be enhanced and the power consumption will be reduced; On the contrary, if the value increased, the resolution will be enhanced, but FPS will be reduced and the power consumption will be increased. Moreover, the maximum value should not larger than 1. Developer can modify the Pixel Density by using the vr.pixelDensity from UE. We provide two ways to use the API：
Use "Execute Console Command" node to modify the "vr.pixeldensity 1.0" command (Please note the Space). We recommand that call it after the Blueprint "EventBeginPlay" .
Open the Path: Project/Config/DefaultEngine.ini，and add "vr.pixeldensity=1" under “[/Script/Engine.RendererSettings]” tag, please refer to the picture below:
The UE official document address：https://www.unrealengine.com/en-US/blog/significant-changes-coming-to-vr-resolution-settings-in-4-19?lang=en-US (opens new window)
Note: The"Plugins-QIYU-SDK-Eye Resolution Scale" of the old versions SDK has been deprecated.
Foveated rendering can optimize the ability to render scenes by providing high resolution for the center of the field of view, and greatly reducing peripheral views the details of the scene. This reduces the GPU load as a result of the reduction in pixel shading requirements. FR can dramatically increase performance, improving the image show in the headset.
Three are three modes: Low, Med and High can be selected. The higher the Foveation Level, the higher the FPS, but the more the pixel loss, which will affect the clarity of the edge area, please choose the appropriate Level according to the rendering needs. Developers can also set the fixation rendering level and parameters through the configuration panel.
With Multi View, objects are rendered once to the left eye buffer, then duplicated to the right buffer automatically with appropriate modifications for vertex position and view-dependent variables such as reflection. It primarily reduces CPU usage, and the GPU performance is unchanged largely. If your application is CPU-bound or draw call bound, we strongly recommend using Single Pass Stereo rendering to improve performance.
Qiyu SDK supports the Mobile MultiView function of Unreal Engine，it can be enabled by check Mobile Multi-View, the path is Project Setting > Rendering > VR > Mobile Multi-View.
Please note that after click or unclick this function, please restart the engine to adapt the settings. Moreover, before enable the Multi View, please turn off the Mobile HDR function.
Vulkan is a high performance and low CPU Utilization graphics APIs, which inherits OpenGL ES. It’s also important to remember that Vulkan, as well as graphics APIs in general, is a CPU API that controls the GPU, so any performance benefits that you might derive from Vulkan will only be of rendering CPU performance, not of GPU performance.
Because of the difference version of Unreal engines, there are different to enable the Vulkan. We suggest developers to use Unreal 4.27 to use Vulkan to develop the game.
Modify the function of IsStandaloneStereoOnlyDevice at EngineSourcePath\Engine\Source\Runtime\Core\Private\Android\AndroidPlatformMisc.cpp as the following below：
bool FAndroidMisc::IsStandaloneStereoOnlyDevice()
{
// Oculus HMDs are always in stereo mode
if (FAndroidMisc::GetDeviceMake() == FString("Oculus"))
{
return true;
}
#if USE_ANDROID_JNI
extern bool AndroidThunkCpp_HasMetaDataKey(const FString& Key);
if (AndroidThunkCpp_HasMetaDataKey(FString("android.device.bQiyuPlatform")))
{
return true;
}
#endif
return false;
}
Please refer to the reference for Unreal 4.26:
Check Support Vulkan and uncheck the SupportOpenGL ES3.1 at Project Settings->Android -> Build.
Note: The C++ type project is recommended.
Using the installing Unreal engine with the following settings:
Check Support Vulkan and uncheck the SupportOpenGL ES 3.1 at project settings->Android -> Build.
Close all the VR plugins (including OpenXR) except QIYU.
Known Issue
Sets the tracking origin type.
Eye: use the headset position and direction as a reference for tracking, and Recenter will restore the position of the virtual camera
Floor: take the ground detected by the headset as the reference plane for tracking, and recenter will not change the height of the virtual camera
Set Floor Eye Type can be used directly in the Blueprint.
The loading Screen of Unreal Engine is not in VR mode. To improve the user experience, Qiyu provide a DIY VR loading Screen function. Please following the steps below:
| Function | Blueprint | Introduction |
|---|---|---|
| GetBoundaryGeometry |  | Get Boundary the value of (X, Y, Z) |
| GetBoundaryDimensions |  | Get the boundary Dimensions |
| SetBoundaryChangeDelegate |  | Set boundary Change Delegate (set the point which used to get the boundary change) |
| Device | QIYU 3 | QIYU Dream |
|---|---|---|
| Manufacturer | iQIYI Smart | iQIYI Smart |
| Headset | QIYU 3 | QIYU Dream |
| Left Controller | QIYU 3 Left Controller | QIYU Dream Left Controller |
| Right Controller | QIYU 3 Right Controller | QIYU Dream Right Controller |
QIYU SDK provides the controller models of QIYU 3 and QIYU Dream, developers can find in Meshes folder, please refer to the screenshot below.
Compositor layers let you render certain forms of content such as text, video, or textures with higher quality than traditional eye-buffer rendering can achieve. Because this will increase the system load, using more than 5 overlay or underlay is NOT recommended.
To use the stereo layer and VR Pawn together, please follow the steps below:
After completing the above steps, you can normally view the stereolayer component in the all-in-one machine, which is not displayed on the PC platform.
The SDK supports the following attributes:
| Name | Description |
|---|---|
| Support Depth | True if the stereo layer needs to support depth intersections with the scene geometry, if available on the platform. |
| Texture | Texture displayed on the stereo layer (if stereoscopic textures are supported on the platform, and more than one texture is provided, this will be the right eye). |
| Stereo Layer Type | Specifies how and where the quad is rendered to the screen. |
| StereoLayerShape | Specifies which type of layer it is. Note that some shapes will be supported only on certain platforms. |
| Priority | Render priority among all stereo layers, higher priority render on top of lower priority. |
Description:
Stereo Layer Type: only support FaceLock and WorldLock in SDK at the moment, the effect of TrackerLock is same as FaceLock.
FaceLock: the relative position between Stereo layer and Camera is constant, and the stereo layer will be rendered in the fixed position.
WorldLock: Stereo layer in world is constant.
StereoLayerShape: SDK only supports Cylinder Layer and Quad Layer。
Cylinder Layer: This type is cylindrical surface. Developers can adjust the radius of the cylindrical surface through the Radius attribute, the arc length of the cylindrical surface through the Overlay Arc attribute, and the height of the cylindrical surface through the Height attribute.
Quad Layer: This type is Quad. Developers can adjust the length and width of the Quad through the Quad size property.
Note: SDK does not support the attributes are not listed in the table above.
QIYU SDK provides 3-Dof selection and blueprint APIs, which added "Neck model" and "Arm model", It can simulate the movement of head and hand naturally.
