Thiết kế flash - Solid modeling – primitives and boolean operations

Solid Modeling – Primitives and Boolean Operations Solid Primitives Primitives are simple solid objects created directly in a CAD systemExamples include: box, sphere, cylinder, cone, wedge, torusModel Building in AutoCADLength - in x axis directionWidth - in y axis directionHeight - in z axis directionLength, width and height can be positive or negative A positive dimension indicates movement in direction of positive axisA negative dimension indicates movement in opposite, or negative directionIn AutoCAD, the following dimensions are associated with the three coordinate axes:Solid CompositesPrimitives combined using Boolean operations to create solid compositesBoolean operations used in solid modeling are: UnionIntersectionSubtraction UnionUnion means set of all elements belonging to either A or BA È BUnion of two or more solids creates a composite solid composed of combined volumes of these solids In set theory, the union of two sets, A and B, is represented pictorially as:IntersectionSet of all elements belonging to both A and BA Ç BIntersection of two or more solidscreates a composite solidcomposed of volume common to original solidsIntersection of two sets, A and B: Subtraction 1Set of all elements belonging to A but not BA – BSubtraction of two solidscreates a composite solidcomposed of volume of first solid minus common volume shared with second solid Subtraction of two sets, A and B: Subtraction 2Alternatively, B - A is represented pictorially as:Solid Modeling – Primitives and Boolean OperationsChega!