Progressive Mesh in DirectX

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Progressive Mesh in DirectX

• 2000160114 Seung ho Lee
• 2000160207 Hyun taek Kwon

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What is Progressive Mesh?

• Level of Detail (LOD)
• Progressive simplification or detail Mesh

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Overview of Progressive Mesh

• Edge collapse or Vertex Split
• Selective Refinement

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Edge collapse or Vertex Split
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Selective Refinement

• Use Vertex History

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The Pipeline of DirectX Mesh

• ID3DXMesh interface
• ID3DXPMesh interface

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ID3DXMesh interface

• General Mesh interface
• Buffers
• Vertex Buffer
• Index Buffer
• Attribute Buffer
• Functions
• DrawSubset(DWORD n)

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ID3DXPMesh

• Progressive Mesh interface
• Make from ID3DXMesh
• Using Progressive Mesh interface

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Implementation

• Implement from ID3DXMesh
• Using Vertex Buffer and Index Buffer
• Class Gmesh
• Vertex Node Tree, History

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Rendering Pipeline
Read PM File
Make GMesh
Write in Mesh Buffer
Draw Mesh
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Result

• Rabbit

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View-Dependent Refinement

1. Definitions
2. Refinement Criteria
3. Implementation

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1. Definitions (1)

• Active vertex, Active face
• A vertex or face is active if it exists
• in the selectively refined mesh Ms.

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1. Definitions (2)

• Vertex hierarchy

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1. Definitions (3)

• Legal

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2. Refinement Criteria

• View frustum
• Coarsen regions outsize the view frustum
• Surface orientation
• Coarsen regions oriented away from viewer
• Screen-space geometric error
• Makes the difference between approximate surface
  M and the original M small

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2. Refinement Criteria (1)
- Bounding Sphere
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2. Refinement Criteria (1)

• Out of View frustum
• Red lines show distance

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2. Refinement Criteria (2)
- Cone of normals
Unnecessary to split if
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2. Refinement Criteria (3)

• Distance
• The distance between the approximate surface M
  and the original M, when projected on the
  screen, is every where less than a screen-space
  tolerance r.

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3. Implementation

• ListNode ActiveVertexHead
• double linked list of active vertex
• ListNode RootVertexHead
• Double linked list of root vertex

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3. Implementation
Active Vertex
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Qrefine()
Split
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