Version: Unity 6 Preview (6000.0)
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Prevent Unity stripping GPU instancing shaders in the Built-In Render Pipeline
Graphics performance and profiling reference

GPU instancing shader reference for the Built-In Render Pipeline

This section contains information about shaderA program that runs on the GPU. More info
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additions that relate to GPU instancing.

Addition Description
#pragma multi_compile_instancing Generates instancing variants. This is required for fragment and vertex shadersA program that runs on each vertex of a 3D model when the model is being rendered. More info
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. It is optional for Surface ShadersA streamlined way of writing shaders for the Built-in Render Pipeline. More info
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.
#pragma instancing_options Specifies options that Unity uses for instances. For information on the option switches available, see #pragma instancing_options.
UNITY_VERTEX_INPUT_INSTANCE_ID Defines an instance ID in the vertex shader input/output structure. To use this macro, enable the INSTANCING_ON shader keyword. Otherwise, Unity doesn’t set up the instance ID.
To access the instance ID, use vertexInput.instanceID inside an #ifdef INSTANCING_ON block. If you don’t use this block, variants fail to compile.
UNITY_INSTANCING_BUFFER_START(bufferName) Declares the start of a per-instance constant buffer named bufferName. Use this macro with UNITY_INSTANCING_BUFFER_END to wrap declarations of the properties that you want to be unique to each instance. Declare properties inside the buffer usingUNITY_DEFINE_INSTANCED_PROP.
UNITY_INSTANCING_BUFFER_END(bufferName) Declares the end of a per-instance constant buffer named bufferName. Use this macro with UNITY_INSTANCING_BUFFER_START to wrap declarations of the properties that you want to be unique to each instance. Declare properties inside the buffer usingUNITY_DEFINE_INSTANCED_PROP.
UNITY_DEFINE_INSTANCED_PROP(type, propertyName) Defines a per-instance shader property with the specified type and name. In the examples below, the _Color property is unique.
UNITY_SETUP_INSTANCE_ID(v); Allows shader functions to access the instance ID. For vertex shaders, this macro is required at the beginning. For fragment shaders, this addition is optional. For an example, see Vertex and fragment shader.
UNITY_TRANSFER_INSTANCE_ID(v, o); Copies the instance ID from the input structure to the output structure in the vertex shader. Use this macro if you need to access per-instance data in the fragment shader.
UNITY_ACCESS_INSTANCED_PROP(bufferName, propertyName) Accesses a per-instance shader property in an instancing constant buffer. Unity uses the instance ID to index into the instance data array.bufferName must match the name of the constant buffer that contains the specified property.This macro compiles differently for INSTANCING_ON and non-instancing variants.

Instancing_options switches

The [#pragma instancing_options](#pragma-instancing_options) directive can use the following switches:

Switch Description
forcemaxcount:batchSize and maxcount:batchSize On most platforms, Unity automatically calculates the instancing data array size. It divides the maximum constant buffer size on the target device with the size of the structure that contains all per-instance properties. Generally, you don’t need to worry about the batch size. However, some platforms require a fixed array size. To specify the batch size for those platforms, use the maxcount option. Other platforms ignore this option. If you want to force a batch size for all platforms, use forcemaxcount. This is useful when, for example, your project uses RenderMeshInstanced to issue draw calls with 256 instanced spritesA 2D graphic objects. If you are used to working in 3D, Sprites are essentially just standard textures but there are special techniques for combining and managing sprite textures for efficiency and convenience during development. More info
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. The default value for the two options is 500.
assumeuniformscaling Instructs Unity to assume that all the instances have uniform scalings (the same scale for all X, Y, and Z axes).
nolodfade Makes Unity not apply GPU instancing to LODThe Level Of Detail (LOD) technique is an optimization that reduces the number of triangles that Unity has to render for a GameObject when its distance from the Camera increases. More info
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fade values.
nolightprobe Prevents Unity from applying GPU instancing to Light ProbeLight probes store information about how light passes through space in your scene. A collection of light probes arranged within a given space can improve lighting on moving objects and static LOD scenery within that space. More info
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values and their occlusion data. Setting this option to ON can improve performance if your project doesn’t contain GameObjectsThe fundamental object in Unity scenes, which can represent characters, props, scenery, cameras, waypoints, and more. A GameObject’s functionality is defined by the Components attached to it. More info
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that use both GPU instancing and Light Probes.
nolightmap Prevents Unity from applying GPU instancing to lightmapA pre-rendered texture that contains the effects of light sources on static objects in the scene. Lightmaps are overlaid on top of scene geometry to create the effect of lighting. More info
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atlas information values. Setting this option to ON can improve performance if your project doesn’t contain GameObjects that use both GPU instancing and lightmaps.
procedural:FunctionName Generates an additional variant for use with Graphics.RenderMeshIndirect. At the beginning of the vertex shader stage, Unity calls the function specified after the colon. To set up the instance data manually, add per-instance data to this function in the same way you would normally add per-instance data to a shader. Unity also calls this function at the beginning of a fragment shader if any of the fetched instance properties are included in the fragment shader.
Prevent Unity stripping GPU instancing shaders in the Built-In Render Pipeline
Graphics performance and profiling reference