| rparams | The parameters Unity uses to render the Mesh primitives. |
| mesh | The Mesh to render. |
| submeshIndex | The index of a submesh Unity renders when the Mesh contains multiple Materials (submeshes). For a Mesh with a single Material, use value 0. |
| instanceCount | The number of instances to render. |
Renders multiple instances of a Mesh using GPU instancing and a custom shader.
This method renders multiple instances of the same Mesh, similar to Graphics.RenderMeshIndirect, but provides the number of instances and other rendering command arguments as function arguments.
Use SV_InstanceID semantic in shaders to access the rendered instance.
The following example uses RenderMeshPrimitives to render 10 Mesh instances. The associated Material must use the below custom shader:
using UnityEngine;
public class ExampleClass : MonoBehaviour { public Material material; public Mesh mesh;
void Update() { RenderParams rp = new RenderParams(material); rp.worldBounds = new Bounds(Vector3.zero, 10000*Vector3.one); // use tighter bounds rp.matProps = new MaterialPropertyBlock(); rp.matProps.SetMatrix("_ObjectToWorld", Matrix4x4.Translate(new Vector3(-4.5f, 0, 0))); rp.matProps.SetFloat("_NumInstances", 10.0f); Graphics.RenderMeshPrimitives(rp, mesh, 0, 10); } }
Use the following example shader with the above C# example code:
Shader "ExampleShader"
{
SubShader
{
Pass
{
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"
struct v2f
{
float4 pos : SV_POSITION;
float4 color : COLOR0;
};
uniform float4x4 _ObjectToWorld;
uniform float _NumInstances;
v2f vert(appdata_base v, uint instanceID : SV_InstanceID)
{
v2f o;
float4 wpos = mul(_ObjectToWorld, v.vertex + float4(instanceID, 0, 0, 0));
o.pos = mul(UNITY_MATRIX_VP, wpos);
o.color = float4(instanceID / _NumInstances, 0.0f, 0.0f, 0.0f);
return o;
}
float4 frag(v2f i) : SV_Target
{
return i.color;
}
ENDCG
}
}
}