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目的

拾遺，備份

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Blend Shape 逐頂點 多個混合思路

blend shape 基于： vertex number, vertex sn 相同，才能正?；旌?、播放
也就是 vertex buffer 的頂點數(shù)量一樣，還有 triangles 的 index 要一致

這樣 blend shape 才能逐個頂點計算

計算公式：使用一張大佬整理的圖，大佬的文章：BlendShapes基礎與拓展練習（面捕與物體變形）

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Blender

Shift+A 新建一個 sphere

選中

Tab 進入 Editor Mode，并且在 Data 頁簽屬性的 Shape Keys 添加對應的 blend shape 狀態(tài)

調整好每一個 Shape Keys (或是叫：blend shape) 的頂點位置
然后再 Object Mode 下，我們可以選中對應的 Shape Keys 然后調整 value 查看變形結果

最終我們嘗試 K幀動畫來查看 多個 shape keys 混合控制的情況

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3Ds max

interlude _1 : working on Yui-chan’s face morphing. - 3Ds max 中的演示 二次元 臉部表情 FFD

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Unity 中使用

先在 blender 導出 fbx

將 fbx 模型拖拽到 hierarchy

嘗試拖拉 inspector 中的 blend shape 拉桿，即可查看效果

所以我們寫腳本控制 blend shape 混合拉桿即可達到我們各種表情的混合控制

在原來 blendshape_1 基礎上在混合 blendshape_2

blendshape_1 和 blendshape_2 一起播放

然后可以嘗試看一下 blendshape_1 和 blendshape_2 不同速率的控制混合的情況
這里使用 pingpong 算法

下面是測試 csharp 腳本

// jave.lin 2023/10/07 測試 blend shapeusing System.Collections;
using UnityEngine;public class TestingBlendShape : MonoBehaviour
{public SkinnedMeshRenderer skinnedMeshRenderer;private int _BlendShape_1_IDX = -1;private int _BlendShape_2_IDX = -1;private IEnumerator _couroutine_blendShape1;private IEnumerator _couroutine_blendShape2;private IEnumerator _couroutine_pingpong;private void OnDestroy(){StopAllCoroutines();}private void Refresh(){if (skinnedMeshRenderer != null){_BlendShape_1_IDX = skinnedMeshRenderer.sharedMesh.GetBlendShapeIndex("BlendShape_1");_BlendShape_2_IDX = skinnedMeshRenderer.sharedMesh.GetBlendShapeIndex("BlendShape_2");}}public void ToBlendShape_1(){Refresh();if (_couroutine_blendShape1 != null){StopCoroutine(_couroutine_blendShape1);}StartCoroutine(_couroutine_blendShape1 = Play_ToBlendShape(_BlendShape_1_IDX, 100.0f));}public void ToBlendShape_2(){Refresh();if (_couroutine_blendShape2 != null){StopCoroutine(_couroutine_blendShape2);}StartCoroutine(_couroutine_blendShape2 = Play_ToBlendShape(_BlendShape_2_IDX, 100.0f));}public void ToBlendShape_1_2(){Refresh();if (_couroutine_blendShape1 != null){StopCoroutine(_couroutine_blendShape1);}StartCoroutine(_couroutine_blendShape1 = Play_ToBlendShape(_BlendShape_1_IDX, 100.0f));if (_couroutine_blendShape2 != null){StopCoroutine(_couroutine_blendShape2);}StartCoroutine(_couroutine_blendShape2 = Play_ToBlendShape(_BlendShape_2_IDX, 100.0f));}public void ToPingPong_BlendShape_1_2(){Refresh();if (_couroutine_pingpong != null){StopCoroutine(_couroutine_pingpong);}StartCoroutine(_couroutine_pingpong = PingPong_BlendShape());}public void StopAll(){StopAllCoroutines();}public void ResetAll(){if (skinnedMeshRenderer != null){var count = skinnedMeshRenderer.sharedMesh.blendShapeCount;for (int i = 0; i < count; i++){skinnedMeshRenderer.SetBlendShapeWeight(i, 0.0f);}}}private IEnumerator Play_ToBlendShape(int idx, float to_val){to_val = Mathf.Clamp(to_val, 0.0f, 100.0f);var start_val = skinnedMeshRenderer.GetBlendShapeWeight(idx);var cur_val = start_val;while (cur_val < to_val){cur_val = Mathf.MoveTowards(cur_val, to_val, (to_val - start_val) * Time.deltaTime);skinnedMeshRenderer.SetBlendShapeWeight(idx, cur_val);yield return null;}Debug.Log($"play to blend shape [{idx}] : [{to_val}] complete!");}private IEnumerator PingPong_BlendShape(){var now_time = Time.time;while (true){var _time = Time.time - now_time;var weight1 = Mathf.PingPong(_time * 200f, 100f);var weight2 = Mathf.PingPong(_time * 50f, 100f);skinnedMeshRenderer.SetBlendShapeWeight(_BlendShape_1_IDX, weight1);skinnedMeshRenderer.SetBlendShapeWeight(_BlendShape_2_IDX, weight2);yield return null;}}
}

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Project

個人備份用

• blender 工程: TestingBlenderShapeKeys.blend
• unity 工程: TestingBlendShape_BRP_2020.3.37f1.rar

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• 百人計劃-BlendShapes基礎（物體變形與面捕應用）
• google : how to implementing the blend shape in blender
• google : how to create shape keys animation in blender
  • Shape Key / Blendshape Hacks to easily create expressions and actions for your avatar
  • Blender 2.8 Shapekeys and Morphing
  • How to Add Shape Keys in Blender
• 形態(tài)鍵
• 在Unity中實現(xiàn)BlendShape表情和骨骼動畫混合的實踐 - 講得挺不錯
• BlendShapes基礎與拓展練習（面捕與物體變形） - 講得挺不錯
• GDC2011: Fast and Efficient Facial Rigging
• GDC jeremy_ernst_fastandefficietfacialrigging.pdf
• 技術美術百人計劃-美術 3.5 BlendShape基礎 筆記
• 3.5 BlendShapes基礎
• 百人計劃-BlendShapes基礎（物體變形與面捕應用）
• 【技術美術百人計劃】美術 3.5 BlendShape基礎
• Unity通過導入器優(yōu)化動畫關鍵幀數(shù)據(jù) - 刪除僅僅只有 blend shape 的動畫的其他骨骼信息，優(yōu)化性能
• interlude _1 : working on Yui-chan’s face morphing. - 3Ds max 中的演示 二次元 臉部表情 FFD