Use the OnDemandRendering class to control and query information about the rendering speed independent from all other subsystems (for example, physics, input, or animation).
Here are some example scenarios of when you may want to lower the framerate:
1. Menus (for example, the application entry point or a pause menu): Menus tend to be relatively simple scenes and as such do not need to render at full speed. You can render menus at a lower framerate to reduce power consumption and to keep the device temperature from rising to a point where the CPU frequency may be throttled.
2. Turn based games (chess for example): Players spend time waiting either for other users to make their move or while thinking about their next move. During periods of low activity, you can lower the framerate to prevent unnecessary power usage and prolong battery life.
3. Applications where the content is static for much of the time such as Automotive UI.
Adjusting the rendering speed will be of particular interest to when using the Adaptive Performance package or simply want to manage power usage and device thermals to maximize battery life and prevent CPU throttling.
Note: On Demand Rendering is not supported for VR applications. Not rendering every frame will cause the visuals to be out of sync with head movement and may increase the risk of motion sickness.
Be aware of the following if you use this with Optimized Frame Pacing on Android:
If you're also using OpenGL ES, Optimized Frame Pacing is most effective when the frame rate is either 20, 30, or 60 frames per second. To make sure that you render at one of these frame rates, use OnDemandRendering.effectiveRenderFrameRate.
Vulkan is less strict and allows a greater number of valid framerates.
If you request an incompatible framerate then the application renders as quickly as possible. Also note that a renderFrameInterval that is too high may lead to the application becoming unresponsive as the time between rendered frames is too large.
Note about event execution:
The diagram on this page describes the execution order for events in each frame. However events that are specific to rendering, including those for Scene rendering, Gizmo rendering, GUI rendering, and End of frame sections, do not occur during frames that Unity does not render (when OnDemandRendering.willCurrentFrameRender is false).
| effectiveRenderFrameRate | The current estimated rate of rendering in frames per second rounded to the nearest integer. |
| renderFrameInterval | Get or set the current frame rate interval. To restore rendering back to the value of Application.targetFrameRate or QualitySettings.vSyncCount set this to 0 or 1. |
| willCurrentFrameRender | True if the current frame will be rendered. |