Static

The Boolean->Static command in the Model module allows you to perform Boolean operations (union, intersection, and difference) on any two objects.

The resulting object is a polygon mesh. For example, if you perform a Boolean intersection using two patch spheres, the resulting intersection object is a polygon mesh.

Tips for Using Boolean Operations

• Make sure that the normals of both objects are correct before you attempt a Boolean operation.
• Problems sometimes occur when points are close together (numerical inaccuracy). Scaling objects by a factor of 10 or 20, freezing them, then scaling them down can make a difference in the quality of the result.
• If the object is complex or has internal curves, holes, etc., scale the centre of the object down as much as possible. In many cases, the results are cleaner.
• Start from simple to complex. For example, if you want a curved surface with holes, grooves, etc., follow these steps:
  • Start with a flat shape that has as few polygons as possible.
  • Cut the required bits away (for multiple holes, use a single merged cutting object).
  • Bevel or round the result if necessary.
  • Subdivide this as much you need to.
  • Patch or curve-fit the result onto a mould object.

Procedure

1. Make sure that the two objects are positioned so that they overlap.
2. Select one of the objects in the Boolean operation.
3. Choose the Boolean->Static command.
   
   The Boolean Operations dialogue box is displayed.
   
   
4. Select one of the three operations: Union, Intersection, or Difference.
5. Select one of the four options for the Resulting Object.
6. Select one of the options for Material.
7. Click Ok to accept the settings or Cancel to exit the dialogue box.
8. Pick the second object used in the Boolean operation.

One or two Boolean objects are created, depending on the options you chose (for Resulting Object).

In the Schematic window, Boolean objects are labelled "booln".

Parameters

Operations

• Union: Processes the two objects and discards the intersecting portions.
• Intersection: Processes the two objects and keeps the intersecting portions.
• Difference: Processes the two objects and keeps all parts of the first object that are different from the second.

Resulting Object

Two objects are created when you perform a Boolean operation. They are subcomponents of the two original objects.

• A and B together merges the two resulting objects.
• A and B separate keeps the two resulting objects separate.
• A only keeps only the first resulting object.
• B only keeps only the second resulting object.

Material

• None defines no material for the resulting object.
• Use object A material copies the first object's material to the resulting objects.
• Use object B material copies the second object's material to the resulting objects.
• Keep respective materials preserves both materials on the resulting object.

Note:
This operation does not copy local textures to the new object.

Remove Unnecessary Edges

If the angle between two polygons is the same, the edge (the line joining two vertices) is removed.

Remove Unnecessary Vertices

If a vertex passes through a straight line between two vertices, it is removed.

Last updated 03-apr-1998