Framerate and Performance Optimization

This page concerns the Vuforia Engine API version 9.8 and earlier. It has been deprecated and will no longer be actively updated.

Accommodate performance-intensive augmented reality apps by setting the performance mode or managing the framerate. Adjusting these settings may result in video on see-through devices running smoother and cause less overheating due to processing and rendering loads.

If the device becomes too hot, the operating system may throttle the app to avoid overheating. Therefore, Vuforia allows you to dynamically adjust the framerate of your digital eyewear app in response to its runtime requirements. You can balance runtime performance against computational load and power consumption, giving you control of your app's performance characteristics.

The recommended framerate API is intended for use with video see-through eyewear devices, to adjust the framerate devices running augmented reality apps.

Optimization can be achieved in two ways in Unity and Native:

• Performance Mode
• Framerate Management
• Setting the Performance Mode and Framerate in Unity
• Setting the Performance Mode and Framerate in Native

When developing apps for Microsoft HoloLens or other video see-through devices there may be situations where the AR experience should last for a longer duration or you need to minimize Vuforia Engine impact on the CPU to allow your own algorithms more time. To limit the extent that the experience may be cut short by battery depletion or performance throttling, a performance mode can be set in the Vuforia Engine API and in the Unity inspector.  

By default, MODE_DEFAULT is used. Change the mode to MODE_OPTIMIZE_SPEED if the Vuforia Engine performance in this mode meets your needs. If you expect the target to be moved continuously, we recommend using in the default mode. 

The Vuforia API provides the getRecommendedFps and setTargetFps methods to obtain and adjust to a recommended render framerate based on your app's rendering and performance requirements. To set a target framerate, call these methods when initializing the app.

The getRecommendedFPS method accepts one or more hints as arguments. The following are the hint flags available for configuring the FPS recommendation:

Manage the maximum framerate on the video see-through device by using the below table for recommended settings for each device. Generally, rendering on the HoloLens always needs to be at 60 fps, while AR rendering on a mobile handheld device can be at 30 fps or at 60 fps, depending on the device.

NOTE: These are only recommended settings. For short AR experiences (less than 10 minutes), it's possible to render at 60 fps:

Setting Performance Mode

Please refer to the following code examples to change the Camera Device Mode in native. Changing the mode should be done after Vuforia::CameraDevice::getInstance().init() and before Vuforia::CameraDevice::getInstance().start().

 // Select the default camera mode:
if (!Vuforia::CameraDevice::getInstance().selectVideoMode(
    Vuforia::CameraDevice::MODE_DEFAULT))
    return false;

or

// Select the default camera mode:
if (!Vuforia::CameraDevice::getInstance().selectVideoMode(
    Vuforia::CameraDevice::MODE_OPTIMIZE_SPEED))
    return false;

Setting the Framerate

Sets the recommended FPS to NONE unless running on an optical see-through device:

private boolean configureRenderingFrameRate()
    {             
        // In this example we selected the default preset hint for best Mobile AR Experience
        // See website documentation for more information on the rendering hint modes 
        // relevant to your AR experience.
        int myRenderingOptions = Renderer.FPSHINT_FLAGS.FPSHINT_NONE;   
        // Retrieve recommended rendering frame rate best on currently configured/enabled vuforia features
        // and selected application hint
        int vuforiaRecommendedFPS =  Renderer.getInstance().getRecommendedFps(myRenderingOptions);
      
        // Use the recommended fps value computed by Vuforia
        if (!Renderer.getInstance().setTargetFps(vuforiaRecommendedFPS))
        {
            Log.e(LOGTAG,"Failed to set rendering frame rate to: " + vuforiaRecommendedFPS + " fps");   
            return false;
        }
        else
        {
            Log.i(LOGTAG,"Configured frame rate set to recommended frame rate: " + vuforiaRecommendedFPS + " fps");        
        }   
        return true;
    }