GPU instancing is a draw call optimization method that renders multiple copies of a mesh with the same material in a single draw call. Each copy of the mesh is called an instance. This is useful for drawing things that appear multiple times in a scene, for example, trees or bushes.
GPU instancing renders identical meshes in the same draw call. To add variation and reduce the appearance of repetition, each instance can have different properties, such as Color or Scale. Draw calls that render multiple instances appear in the Frame Debugger as Draw Mesh (instanced).
This section includes information about the platform, render pipeline, and SRP Batcher compatibility of GPU instancing.
GPU instancing is available on every platform except WebGL 1.0.
|機能||Built-in Render Pipeline||Universal Render Pipeline (URP)||HD レンダーパイプライン (HDRP)||Custom Scriptable Render Pipeline (SRP)|
|GPU instancing||可||Yes (1)||Yes (1)||Yes (1)|
GPU instancing isn’t compatible with the SRP Batcher. The SRP Batcher takes priority over GPU instancing. If a GameObject is compatible with the SRP Batcher, Unity uses the SRP Batcher to render it, not GPU instancing. For more information about optimization method priority, see Optimization priority.
If your project uses the SRP Batcher and you want to use GPU instancing for a GameObject, you can do one of the following:
Unity uses GPU instancing for GameObjects that share the same mesh and material. To instance a mesh and material:
To use GPU instancing for a material, select the Enable GPU Instancing option in the Inspector.
GPU instancing supports Unity’s Baked Global Illumination system. Unity Standard Shaders and surface shaders support GPU instancing and Unity’s Baked Global Illumination system by default.
Each GPU instance supports global illumination from one of the following sources:
GPU instancing automatically works with:
To enable Light Probe rendering for
Graphics.DrawMeshInstanced, set the LightProbeUsage parameter to CustomProvided and provide a MaterialPropertyBlock that includes the Probe data. For more information and code examples, see LightProbes.CalculateInterpolatedLightAndOcclusionProbes.
Alternatively, you can pass an LPPV component reference and LightProbeUsage.UseProxyVolume to
Graphics.DrawMeshInstanced. When you do this, all instances sample the volume for the L0 and L1 bands of the Light Probe data. If you want to supplement L2 data and occlusion data, use a
MaterialPropertyBlock. For more information, see Light Probes: Technical Information.
Meshes that have a low number of vertices can’t be processed efficiently using GPU instancing because the GPU can’t distribute the work in a way that fully uses the GPU’s resources. This processing inefficiency can have a detrimental effect on performance. The threshold at which inefficiencies begin depends on the GPU, but as a general rule, don’t use GPU instancing for meshes that have fewer than 256 vertices.
If you want to render a mesh with a low number of vertices many times, best practice is to create a single buffer that contains all the mesh information and use that to draw the meshes.