# Use the GPU Resident Drawer

The GPU Resident Drawer automatically uses the [`BatchRendererGroup`](https://docs.unity3d.com/Manual/batch-renderer-group.html) API to draw GameObjects with GPU instancing, which reduces the number of draw calls and frees CPU processing time. For more information, refer to [How BatchRendererGroup works](https://docs.unity3d.com/Manual/batch-renderer-group-how.html).

The GPU Resident Drawer works only with the following:

- [Graphics APIs](https://docs.unity3d.com/6000.0/Documentation/Manual/GraphicsAPIs.html) and platforms that support compute shaders.
- GameObjects that have a [**Mesh Renderer** component](https://docs.unity3d.com/Manual/class-MeshRenderer.html).

Otherwise, Unity falls back to drawing the GameObject without GPU instancing.

If you enable the GPU Resident Drawer, the following applies:

- Build times are longer because Unity compiles all the `BatchRendererGroup` shader variants into your build.

## Enable the GPU Resident Drawer

To enable the GPU Resident Drawer, follow these steps:

1. Go to **Project Settings** > **Graphics**, then in the **Shader Stripping** section set **BatchRendererGroup Variants** to **Keep All**.
2. Go to the active [HDRP Asset](HDRP-Asset.md), then in the **Rendering** section set **GPU Resident Drawer** to **Instanced Drawing**.

If you change or create GameObjects each frame, the GPU Resident Drawer updates with the changes.

To include or exclude GameObjects from the GPU Resident Drawer, refer to [Make a GameObject compatible with the GPU Resident Drawer](make-object-compatible-gpu-rendering.md).

## Analyze the GPU Resident Drawer

To analyze the results of the GPU Resident Drawer, you can use the following:

- [Frame Debugger](https://docs.unity3d.com/Manual/FrameDebugger.html). If the GPU Resident Drawer groups GameObjects, the Frame Debugger displays draw calls called **Hybrid Batch Group**.
- [Rendering Debugger](rendering-debugger-window-reference.md)
- [Rendering Statistics](https://docs.unity3d.com/Manual/RenderingStatistics.html) to check if the number of frames per second has increased, and the CPU processing time and SetPass calls have decreased.
- [Unity Profiler](https://docs.unity3d.com/Manual/Profiler.html)

## Optimize the GPU Resident Drawer

How much the GPU Resident Drawer speeds up rendering depends on your scene. The GPU Resident Drawer is most effective in the following setups:

- The scene is large.
- Multiple GameObjects use the same mesh, so Unity can group them into a single draw call.

Rendering usually speeds up less in the Scene view and the Game view, compared to Play mode or a final built project.

The following might speed up the GPU Resident Drawer:

- Go to **Project Settings** > **Player**, then in the **Other Settings** section, disable **Static Batching**.
- Go to **Window** > **Panels** > **Lighting**, then in the **Lightmapping Settings** section enable **Fixed Lightmap Size** and disable **Use Mipmap Limits**.

## Additional resources

- [Reduce rendering work on the CPU](reduce-rendering-work-on-cpu.md)
- [Graphics performance fundamentals](https://docs.unity3d.com/Manual/OptimizingGraphicsPerformance.html)
- [GPU occlusion culling](gpu-culling.md)