关于简化

简化原因

• 冗余数据：信息熵
• 在不损失视觉效果的情况下减少数据量
• Level of details (LOD)

Simplification Applications

• Level‐of‐detail modeling
  • Generate a family of models for the same object with different polygon counts
  • Select the appropriate model based on estimates of the object's projected size
• Simulation proxies
  • Run the simulation on a simplified model
  • Interpolate results across a more complicated model to be used for rendering

Tradeoff

• Size
• Error
• Quality

简化算法

Performance Requirements

• Offline
  • Generate model at given level(s) of detail
  • Focus on quality
• Real‐time
  • Generate model at given level(s) of detail
  • Focus on speed
  • Requires preprocessing
  • Time/space/quality tradeoff

简化目标

顶点删除 [图54:51]

方法一

v ← v‐1，f ← f‐2
Remaining vertices是subset of original vertex set

方法二

Pair contraction (cluster of two vertices)
Vertices may move

边收缩 [图56:46] Edge collapse

方法一

v ← v‐1，f ← f‐2
Vertices may move

方法二

Cluster contraction (set of vertices)
Vertices may move

面 Triangle collapse

方法一

v ← v‐2，f ← f‐4
Vertices may move

方法二

聚类法：[57:46]，画格子，格子内的三角形收缩、点合并会产生非流型和悬挂边

Merge all vertices within the same cell

简化度量

• 几何
• 视觉：纹理、材质、法向…

Local vs. Global Error

全局优于局部，具体见下一页

本文出自CaterpillarStudyGroup，转载请注明出处。 https://caterpillarstudygroup.github.io/GAMES102_mdbook/