Intro to Rhinoceros 3D

Rhino Tutorial

Resources:

  • CMU ArtFab Rhino-101
    • Great resource. Keep this open when you’re working. Keep it open for this workshop
  • Lynda Rhino Tuturials
    • These are the best tutorials we can find on the web. Time consuming, but pretty comprehensive. If you plan on using Rhino in the future, take time to follow these tutorials.

What is Rhino and when should I use it?

  • Rhinoceros is a 3D modeling tool for Windows and OSX. It uses a NURBS model, as opposed to a polygon-based model. This allows for the development high-precision free-form shape-making.
  • Plugins Rhino has opened their plugin SDK, which has allowed several developers to produce useful plugins for the program. Rhino also has the Grasshopper plugin, which allows you to create algorithmic, parametric geometries that can be manipulated with outside data or from internal GUI sliders in real-time.

  • CMU Arts Rhino has become the go-to 3D modeling software for much of the digital fabrication facilities in CFA. Architecture dFab and Art’s ArtFab CNC machines (as well as Ideate’s CNC) all use RhinoCAM, which plays well with Rhino3d.

Getting Started

Setting Up a New File

Units

Since much of what we do in Rhino is intended to be produced in real life or to mimic real places and things, our choice of units is important.
– File > Settings > Units | (or just type units and hit enter)
– For the Ideate Laser Cutter, choose millimeters.
– Two options, ‘Model’ and ‘Layout’
– How to Choose:
– Is this a part to be integrated into a system?
– Is this something that will be placed in an American or on an American building? (inches/feet)
– Is this going in VR? (who cares)
– etc.
– ‘Distance Display’: change this depending on your units. if using inches or feet, you probably want your distances to show up like “3ft 2in”.

Grid

  • Go to the ‘Grid’ heading in the settings section. Choose the units that match your model. You may want to change your grid ‘minor grid’ and ‘major grid’ to match conventions (12 inches per foot, etc).
  • The grid in Rhino is centered, so the origin is in the middle of the grid, where the red and green lines meet. Looking from the top viewport, position numbers increase as you move right and up.

Using Tools

  • Unlike Illustrator, Photoshop, in which users use toolbars, drop down menus, etc to access functionality, Rhino relies on typed commands.
    • For example, if we want to draw a rectangle, we don’t click on the rectangle icon. Instead we just start typing “rectangle”
      • You do NOT need to click inside the dialog box to bring up a tool. Just start typing.

Terms

  • Curve
    • Lines, paths
  • Surface
    • Think a piece of fabric
  • Solid
    • A series of surfaces that are combined and “airtight”

Exercises

1) Laser Cutting — Making a Platonic Solid

In three-dimensional space, a Platonic solid is a regular, convex polyhedron. It is constructed by congruent regular polygonal faces with the same number of faces meeting at each vertex. Five solids meet those criteria: Tetrahedron, Cubes, Octahedron, Icosahedron, and Dodecahedron.

We are going to make a Net (a representation of all of the sides of a solid, unfolded) for the solid of your choice, complete with tabs and variable linetypes, so you can laser cut and assemble your own solids.

Modeling

  1. Pick a solid.
  2. Determine what basic shapes that solid is made of:
    • Tetrahedron — 4 × equilateral triangles
    • Cube — 6 × squares
    • Octahedron — 8 × equilateral triangles
    • Icosahedron — 12 × equilateral triangles
    • Dodecahedron — 20 × pentagons
  3. Using the polygon command, draw a single copy of your basic shape, scaled to the size you want to cut.
  4. copy, move, and rotate the shape n times, until you have a full Net for your shape. You will have to envision the shape in 3D, and how the net will fold into that shape in order to do this correctly.

  1. Create well-sized tabs, like in the image above, and copy, move, and rotate them into place around your solid.
  2. Make two new layers, CUT and SCORE, and change their layer colors to rgb(255, 0, 0) and rgb(0, 0, 255) respectively.
  3. Determine what lines should be CUT and what lines should be SCOREd, and move them to their respective layers. Be careful not to have multiple lines occupying the same space, especially if they’re on different layers; the laser cutter will cut them twice. explodeing the shape.

Laser Cutting

  1. Use theexport command to bring up a “Save As” dialog. Use the drop down to select ‘AutoCAD Drawing Exchange (dxf)’
  2. Follow the Ideate Tutorial for transferring your drawing to the Laser Cutter and cutting.

2) 3D Printing — Making a Solid of Constant Width

In geometry, a surface of constant width is a convex form whose width, measured by the distance between two opposite parallel planes touching its boundary, is the same regardless of the direction of those two parallel planes.

We are going to make an assortment of these solids to 3D print.

Modeling

  1. Draw a polygon, either an equilateral triangle, a pentagon, or a septagon.
  2. Draw a circle centered around each vertex of the shape, so its circumference lies on the two vertices on the opposite side of the shape.
  3. trim away all of the extra lines, so that you’re left with the shape you started with that has round legs instead of straight ones.
  4. revolve the shape around its symetrical axis, so that you have a full 3D solid.
  5. Scale the solid so that it’s width is reasonable. If you’re making multiple solids of different type, make sure all of the widths are the same.

Printing

  1. For a 3D model to be printable on a 3D printer, it needs to be ‘water tight’, without any holes or open edges. This generally means it is all closed polysurfaces.
    1. Check for open polysurfaces with showEdges, making sure you choose the “select open polysurfaces” option.
    2. You can often fix issues by using joinedges command or by creating a new surface to cover any gaps.
  2. Turn the model into a mesh.
    1. Sometimes, fillmeshhole and fillmeshholes can be used to fix naked edges in the mesh.
    1. Make sure to save your NURBS model before this operation as it is difficult or impossible to reverse.
  4. Export the mesh as a binary STL file.
  5. Save the file on a flash drive and bring it to one of the IDeATe monitors to print, according to the instructions here