1 Edgar L. Coffey Applied Research Associates, Inc. November 14, 2006 Advanced Features.

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Edgar L. CoffeyApplied Research Associates, Inc.

November 14, 2006

Advanced Features

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New SmartView Features/Tools

• Decimation

• Tessellation

• Rotate/Translate/Scale

• Whole-Object Smoothing

• Copy/Paste

• Error/Integrity Checking

• Model Editing

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Decimation – Simplifying the Model

• 3 methods implemented– Remove common edge– Remove redundancies– Remove common point

• User directs execution– Methods are independent– Visual feedback

• Preserves original model– Always revert to original– Must commit to keep

decimation

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Decimation by Removing Common Edge

We can safely remove an edge common to two polygons if:

• The edge’s wedge angle is less than Max. Wedge Angle.

• Removing the edge doesn’t cause new surface to deviate from the old by more than the surface tolerance.

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Decimation by Removing Redundancies

We can safely remove a point connecting parallel lines if:

• Removing the point doesn’t cause new line to deviate from the old by more than the Edge Tolerance.

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Decimation by Removing Common Points

We can safely remove a point common to several polygons if:

• Removing the point doesn’t cause new surface to deviate from the old by more than the Surface Tolerance.

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Decimation Example: Crusader

Before: 6,324 polys

After: 513 polys

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Tessellation – Re-faceting the Model

• Each poly is divided into many, according to the Edge Length parameter.

• A poly’s Mesh Factor influences the fineness of the mesh.

• New mesh retains edge connectivity.

• Each poly’s mesh can be smoothed for better model integrity.

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Tessellation Example – Simple Engine Model

Before: 90 polys

After: 4,862 polys

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Tessellation Example –EA-6B

Before: 2,241 polys

After: 34,411 polys

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Tessellated EA-6B Close Up

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Tessellation of DDG-51

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Rotation, Translation and Scaling

• Transform steps:– Scale model– Rotate as specified– Transform as specified

• Make multiple copies• Use selection only• Preserve original model

– Always revert to original– Must accept to keep

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Creating a Helix Array from One Point

• Steps to create figure– Create point at (0.1,0,0).– Transform point once.

• Rotate RZ 20°• Translate Δz = 0.01 m

– Make wire between the two points.

– Transform model 100x to make first spiral

• Rotate RZ 20°• Translate Δz = 0.01 m

– Translate model once to make 2nd spiral: Δx = 0.6 m

– Translate model once to make 3rd/4th spirals. Δy = 0.6 m

– Save model (404 segments)

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Whole-Object Model Smoothing

• Smooth mesh across entire model– Selection only option– Laplace smoothing– Select iterations– Apply fraction of force– Stop when converged

• Repeatedly apply– Visual feedback

• Too much smoothing will shrink model!!!– Use fixed points– Use selections

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Smoothing Example – F-16 Model

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Copy/Paste Between Models

F16 MOM Model

F16 GTD Model

F16 GTD Pasted into F16 MOM

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SmartView Error and Integrity Checking (1)

• SmartView can check the validity of your model via a set of integrity measures.– Mesh, patches,

segments, junctions, connections.

• Upon completion, the model will be colored green/yellow/red for ok/warning/error.

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SmartView Error and Integrity Checking (2)

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Results of Integrity Checks

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Rendering of Wire Mesh Modeling Errors

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Error Dialog for Wire Mesh Models

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Editing Methods in SmartView

• Menus/Dialogs/User entry– Works in all view modes– Some actions require selections– Add, delete, modify points and polys

• Mouse commands/popup actions– Works only in edit mode– Contextual popup menus define actions– Add, delete, modify points and polys– Higher order actions depending on context

• Combine adjacent polys into one poly• Split a poly into two polys• Split an edge into two or three edges

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Adding Elements from the Menu

Apply/Revert before committing change.

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Deleting Elements from the Menu

Point/poly number automatically increments for user’s convenience.

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Editing Selection from the Menu

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Mouse Actions in Edit Mode (1)

Start

Stop

Left click and drag to opposite corner

After release

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Mouse Actions in Edit Mode (2)

Right click on unselected point

Right click on unselected poly

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Mouse Actions in Edit Mode (3)

Double-click selects and deselects points and polys

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Mouse Actions in Edit Mode (4)

• Context-Sensitive Action List– Close– Delete Selection– Fix Points (make immovable)– Unfix Points– Remove Redundant Points– Combine Polys– Split Poly– Create Poly from Points– Split Edge X2– Split Edge X3– Flip Normals– Add Point on PolyRight click on selection

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Mouse Actions in Edit Mode (5)

Shift-Left Click and Drag on Unselected Point

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Correcting a Modeling Error - Animation

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Advanced Feature Demonstration

• Multiple models– Read them into memory– Switch between models– Copy and paste between models

• Simple editing – File → Edit options– Build the 4-helix antenna array

• Decimation• Tessellation• Advanced Editing

– Edit mode editing– Mouse actions– Add/modify/delete– Surface crawls

• Error Checking– F-16 demonstration– Error/integrity parameter review

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SmartView Advanced Hands-On (2)

• Editing practice – Make the four-helix array on slide #14

• Decimation practice– Decimate CrusaderTri.pnt– In SV/examples/Decimation/Crusader

• Tessellation practice– Tessellate your decimated Crusader– Use a mesh size of 0.1 m

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SmartView Advanced Hands-On (2)

• “Fix” the F-16 model in f16.pnt– Just do one half (other is symmetric)– Copy f16.pnt to something else!– Use the Error mode to find problems

• Reversed normals• Disconnected polygons• Polygon areas too big

– Use Tools → Revisualize Model– Don’t forget to save often!