Version: 2022.3
  • C#


struct in UnityEngine


Implemented in:UnityEngine.CoreModule

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Describes 4 skinning bone weights that affect a vertex in a mesh.

Elements in this struct must be in descending order of weight value. The sum of all weight values must be 1. If a vertex is affected by fewer than 4 bones, each of the remaining weight values must be 0.

Note that this struct, and the associated Mesh.boneWeights and Mesh.GetBoneWeights APIs, describe exactly 4 bone weights per vertex. The newer BoneWeight1 struct describes a single bone weight, and it can be used with the associated Mesh.GetAllBoneWeights, Mesh.SetBoneWeights and Mesh.GetBonesPerVertex APIs to describe up to 255 bone weights per vertex. It is preferable to use BoneWeight1 and its associated APIs; they offer more flexibility, and might result in small performance benefits as Unity does not have to perform unnessary conversion operations.

Additional resources: Mesh.boneWeights, Mesh.GetBoneWeights, Mesh.GetAllBoneWeights, Mesh.SetBoneWeights, Mesh.GetBonesPerVertex, ModelImporter.maxBonesPerVertex, QualitySettings.skinWeights, SkinnedMeshRenderer.quality.


boneIndex0Index of first bone.
boneIndex1Index of second bone.
boneIndex2Index of third bone.
boneIndex3Index of fourth bone.
weight0Skinning weight for first bone.
weight1Skinning weight for second bone.
weight2Skinning weight for third bone.
weight3Skinning weight for fourth bone.