Procedure for Creating VRML Output File from CAD Geometry in CATIA

CATIA
Generate or Load a body

Go to pull down menu, and select “Start”, “Analysis & Simulation”, and “Advanced Meshing Tools” in order. Then, a popup window for selecting analysis case will appear. Select “Static Analysis”.

Click the “Surface Mesher” icon, and then select “Part Body”. This will show a pop-up window. Push the “More >>>” button, and set all variables, e.g. Element shape, Mesh size, Constraint sag, etc.. Guidance on these parameters is provided below:
· There are two options for the cell shape, i.e. triangular and quadrilateral.
· The mesh size should be small enough to follow the curvature of the body. User experimentation may be helpful in balancing the number of surface mesh and surface definition accuracy.
· All zero-values are recommended for the offset and the minimum holes size.
· All zero-values are recommended for the angles between faces and curves. Otherwise, in case of smoothly curved wall, it is not easy to resize the mesh in the desired regions.
Once all parameters are specified, press “OK”.

From the resulting picture click the “Mesh the Part” icon. The body surface panels will then be generated.

If you want to reduce or increase the number of panels in a specific area, press “Remesh Domain” button, and modify the mesh size in the pop-up window. When you want to mesh again, click “Remove Mesh” button and “Mesh the Part” button again.

When the mesh generation is complete, press the “Exit” button.

If an older revision of CATIA us used (CATIAv5R6), then additional steps are needed.
a. After body is generated, go to the pull down menu and select “Start”, “Mechanical Design”, “Wireframe and Surface Design” in sequence.
b. Press the “Extract” button in the tool box located on the right hand side. Repeat this until all surfaces are extracted from the solid body.
c. From the pull down menu, select “Insert”, “Operations”, and “Join” to make one object that consists of several surfaces. If the “Join” operation does not work and has an error, then there is a connectivity problem. In this case, a small gap might exist between neighboring surfaces. Make sure that all surfaces should be connected with each other. Otherwise, try the “Healing” operation. However, “Healing” operation is not normally recommended, since it may generate an arbitrary surface between two disconnected surfaces. Case must be exercised by the user to ensure proper connectivity between the surfaces.
d. Go to the first Step above, and follow the remainder of the procedure.

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