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Unity Engine

CombineMeshes(CombineInstance[], bool, bool, bool)

Combines several Meshes into this Mesh.
Read time 2 minutesLast updated 9 days ago

Definition

  • Type: Method
  • Namespace: UnityEngine
  • Assembly: UnityEngine.CoreModule
public void CombineMeshes(CombineInstance[] combine, bool mergeSubMeshes, bool useMatrices, bool hasLightmapData)

Parameters

combine

CombineInstance[]
Descriptions of the Meshes to combine.

mergeSubMeshes

bool
Defines whether Meshes should be combined into a single sub-mesh.

useMatrices

bool
Defines whether the transforms supplied in the CombineInstance array should be used or ignored.

hasLightmapData

bool
Defines whether to transform the input Mesh lightmap UV data using the lightmap scale offset data in CombineInstance structs.

Remarks

Combining meshes can improve performance by reducing the number of renderers needed to render a scene.
If 
mergeSubMeshes
is set to true, all CombineInstance instances are combined into a single sub-mesh. If set to false, each instance is placed in its own sub-mesh in the resulting mesh. Set this to true when all instances share the same material and topology for optimal performance.
When 
useMatrices
is set to true, the vertices in each CombineInstance are transformed with the instance’s CombineInstance.transform matrix. Otherwise, the transform matrices are ignored and the vertices are combined without modification. This parameter allows you to combine meshes into a common space. To ensure meshes align correctly in the combined mesh, temporarily reset the position and rotation of the combined Mesh's destination MeshFilter to zero before combining, and restore them afterward.
Set 
hasLightmapData
to true to transform the input Mesh lightmap UV data using the lightmap scale offset data in CombineInstance structs. The Meshes must share the same lightmap texture.
Note that meshes must be readable from the CPU to be combined. If a mesh is not CPU-readable, Unity logs a warning in the console and ignores the instance.
using UnityEngine;// This script combines the meshes from children into a single new Mesh.// The combined mesh is assigned to the MeshFilter of this GameObject.// The original meshes are not destroyed, but their GameObjects are deactivated.[RequireComponent(typeof(MeshFilter), typeof(MeshRenderer))]public class ExampleClass : MonoBehaviour{    void Start()    {        MeshFilter[] meshFilters = GetComponentsInChildren<MeshFilter>();        CombineInstance[] instances = new CombineInstance[meshFilters.Length];        for (int i = 0; i < meshFilters.Length; i++)        {            var meshFilter = meshFilters[i];            instances[i] = new CombineInstance            {                mesh = meshFilter.sharedMesh,                transform = meshFilter.transform.localToWorldMatrix,            };            meshFilter.gameObject.SetActive(false);        }        Mesh combinedMesh = new Mesh();        combinedMesh.CombineMeshes(instances);        gameObject.GetComponent<MeshFilter>().sharedMesh = combinedMesh;        gameObject.SetActive(true);    }}
Additional Resources: Mesh.isReadable, MeshTopology.