ucsd-compfab

Week 2.1 - Laser to 3d: Stacked Contours

Agenda

• Artist of the Day
• Extruding Curves
  • Example File: Extruding curves
  • Video Demo: Extrusion
• Stacked Contours from a Mesh
  • Working with meshes
    • Example File: Creating Meshes
  • Importing meshes
    • Example File: Buffalo Contours
    • Example File: Sliced Pikachu
  • Video Demo: Extracting Contours from Mesh
• Homework

Artist(s) of the Day

Ben Butler - various projects

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Ekene Ijeoma - Wage Islands

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Maya Lin - Topologies

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Extruding Curves

• We can extrude a 2d curve into 3 dimensions to see what it would look like as a flat object.
  • ExtrudeCrv <— THIS IS OUR GOTO
• Load up your tab and slot construction from last week (or make a new one).
• If you have not already, join the perimeters for each of the pieces so that you have continuous outlines.
• Extrude the curves into three dimensions using Extrude Curve.
• Use the transformations and object snaps to assemble your pieces together into a virtual model:
  • Move
  • Rotate
  • object snaps
• Take a screenshot (ViewCapture) and save to file.
  • Rotate the viewport to capture a number of different vantage points.
  • Experiment with the Display Options to choose an aesthetically pleasing render.

Example File: Extruding Curves

Rhino file: stacked_contours_offset.3dm

Workflow:

• draw some curves using the 2d drawing tools (Curve, Line, Trim/Join, etc.)
• Offset
• ExtrudeCrv
• Move the curves into position, stacking them vertically.

Video Demo: Extrusion

Extrusion Demo (google drive video)

Stacked Contours From Mesh

Working With Meshes

Solids vs. Meshes

• Solids
  • what are they? (collections of surfaces)
  • explode, cap
  • when we export STL we are creating a mesh
• Meshes
  • Create meshes directly

Example File: Creating Meshes

Rhino file: solids_meshes.3dm

Importing Meshes

• Importing - Import
  • STL file - Stereolithography (wikipedia definition)
  • buffalo.stl
  • Rotate, Scale, and translate as necessary to find and position the object. Also, Zoom Extents
• Simplification (MeshReduce)
  • buffalo_reduction.3dm
• Edit directly - PointsOn, and directly manipulating points on the mesh.
• Closed vs Open Meshes
  • We need closed meshes for 3DP. Object properties will tell you if a mesh is an open or closed mesh.
  • Attempt to patch an open mesh: Mesh -> Repair Tools -> Fill All Holes
  • Rhino Mesh Repair tools

Extracting Contours from a Mesh

Clean up the Mesh

• Importing and slicing a complex mesh
  • Finding a mesh (thingiverse.com)
  • Importing a mesh into rhino
  • Slicing a mesh with the contour command
  • slicing/design for digital fabrication (material thickness considerations)
• Simplifying mesh
  • ReduceMesh
• Go from mesh to unrollable surface:
  • MeshToNURB

the NEW way (Rhino 8)

• In the top view, select your object and create a ClippingSection centered on the origin.
• In the front view, use Array to copy the sections. Try 1 for X, 24 for Y, 1 for Z.
• Select your stack of ClippingSections, and use NestedClippingDrawing to create a flat layout of those clipped sections.

Reference: see Sectioning for Fabrication https://www.rhino3d.com/stories/fabrication/sectioning-for-fabrication/

Example File: Buffalo Clipping Sections

Rhino file: buffalo-clipping-sections.3dm

the OLD way

• Slicing a 3d mesh or surface object into 2d stacks
  • the contour command
  • contour_command.3dm
  • contour_shear_flatten.3dm

Example File: Buffalo Contours

Rhino file: buffalo_contours.3dm

Example File: Sliced Pikachu

Rhino file: sliced_pikachu.3dm

Video Demo: Extracting Contours from Mesh

Video Demo Meshes and extracting contours (google drive video)

Homework

• Finish Exercise 2: 3D Tab and Slot (canvas submission) DUE Thursday 10/10, Design and Fabricate

Leftovers

• Slicing / panelling tools (breaking 3d structure down into 2d components that can be assembled)
• Parametric design for kerfs and 3d structures (grasshopper)