Why Surfaces? Solid models need to follow these rules: 1. Every edge must be a boundary between exactly two faces. 2. Must always be a „water-tight‟ volume.
Why Surfaces? Surfaces provide design flexibility: • Create geometry one surface at a time rather than one chunk at a time. • Solid modeling tools are simply „automated surfacing tools‟. shell = delete face + thicken
Solids to Surfaces & Surfaces to Solids Solids to Surfaces: solid 1. Copy (Offset) Surface 2. Delete Face copy surface 3. Knit Surface delete face Surfaces to Solids: 1. Knit Surface & Try to Form Solid knit surfaces 2. Thicken & Create Solid from Enclosed Volume thicken
Bag of Surfacing Tricks• Fixing/Modifying imported geometry Simplify imported geometry – (Delete & Patch) Repair/Modify imported geometry – (Extrude surface, Replace face) Repair sheet metal import – (Copy surface, Face fillet, Thicken)• Overcoming Solid Modeling Challenges Extrude offset from multiple surfaces – (Knit surface) Extending countersinks – (Copy surface, Extend surface, Cut with surface) Extrude/Cut normal to curved surface – (Split line, Copy surface, Thicken cut) Complex variable radius fillets – (Split line, Face fillet with hold line) Complex ruffled surfaces – (Revolved surface, Split line, Delete face, Surface loft)
Simplifying Imported Geometry – Delete & Patch Using the „Delete Face‟ command with the „Delete and Patch‟ option selected will delete the selected faces and extend the surrounding faces to patch the gap.
Modifying/Repairing Imported Geometry – Replace Face
Checking Imported Sheet Metal Part File • Golden sheet metal rules: 1. Must be uniform thickness throughout the entire part 2. All bent surfaces must either be cylindrical or conical • Check to see if bends are cylindrical/conical: Cut a section normal to the bend axis, click on the arc, and check for radius measurement • Check to see if flat faces are actually flat: Click on “flat” face, and check for “Sketch” icon • Check thickness using measure tool • RMB > „Select Tangency‟
Repairing Imported Sheet Metal Parts import delete & patch copy surface delete body delete face extend / untrim face fillet thicken insert bends & flatten
Extrude Offset from Multiple Surfaces – Knit Surface extrude offset from surface translate OFF knit surface*or (in 2011), you can create the same result by using a split extrude offset from surface line and an extrusion off the 3D faces. translate ON