Notes from newbeginner's 3D workshop by Marie Dahlén at Fabriken

Date: 2014-03-08
Location: Fabriken / Stapeln
Tutor: Marie Dáhlen

Intro

Two kinds of 3D: Polygon or Nurbs

Polygon

• Vertex points that are combined to make a polygon

Nurb

• More formulas for shapes - become rendered into polygons
• If you want to do a vase you can keep a smooth curve - "high tesselation of the polygons"
• For asymmetrical things, polygons are easier because you can extrude the surfaces you want to alter.
• Rhinoceros is a good tool for modelling nurbs

Topology

Sketchup does polygon modelling. Unfortunately it's hard to see the topology - how the polygons are built up.

In 3D printing, topology is very important. Weird "twisted" polygons are bad.

Programs to show the topology

• K-3D - free 3D modelling and animation software. Easy to see topology.

25 (Free) 3D Modeling Applications You Should Not Miss

Illustrator

It's possible to export shapes from Illustrator and get them into some 3D editors.

Photoshop CC

Now it's possible to create 3D shapes and even print them, all inside Photoshop CC.

Sketchup walkthrough

• You can create a new project with millimeters
• View - Tool palettes - Large toolsets
• The pallet instructor is a good help for newbies
• Good resource: sketchup.com > Learn > Video Tutorials
• The left palette is similar to the palette in Photoshop - but for rectangles
• Click and drag to create a polygon, then click again to finish.

Now we have a rectangle.

• Push / pull, drag up to create a cube
• Scroll to zoom in/out
• Push the middle button to pan around

Now we have a cube.

• Use the line tool to split into multiple polygons
• Move mouse slowly - when it snaps it's in the middle

• Move tool - select vertices and move them around
• You can also combine multiple objects using this tool

• Create a circle - make it a cylinder
• Select an object, use the move tool, move it into the cube
• Select both, Edit > Intersect Faces > With selection

Now we have a combined shape.

• View > Hidden geometry - shows the vertices of the shapes
• In Sketchup, you can't edit the vertices
• View > Face style > X-ray / Wireframe, different ways to see the model
• Vertices inside shapes are bad - select vertices inside of the joined shape to remove them

Other tools

Follow me

• Make an edge, for example using Arc tool
• Select the Follow Me tool
• Push the edge away from the geometry - to nicely create a "chamfer"
• If you need to clean up afterwards, use the eraser tool

Freehand tool

Draw a freehand shape and extrude it into a solid object.

Offset tool

• Select the Offset tool
• Drag out a surface inside another surface
• Use push/pull tool to push the surface down (or up)
• You have created a solid inside!

Tips about workflow

File handling

• 3D programs tend to crash
• Files tend to be corrupted
• Save your files often
• Save different versions of files - for instance append a number at the end of the filename
• Sketchup auto-saves by default every 5 mins, also creates backup file

Do alterations of same object, keep them all in same scene

• Show / hide geometries
• Edit > Hide (Apple+E) to hide object

Prepare for 3D printing

• You must have solid objects (both an outside and inside / a "thickness")
• You can preview your model in Slic3r to see if it will work
• When something is sticking out to the side, you need support structure (work against gravity)
• Cura, Slic3r, Mesh Mixer can create support structure
• You might want to rotate the object to get a better structure
• Sometimes you might want to slice your object into multiple pieces (for instance a globus) and then glue them together after they are printed

File format

STL

Most 3D programs print from .STL, but in Sketchup you need to download the extension to export to STL.

File > Export STL...

Working with other 3D programs

It's common to do quick sketches in Sketchup and then keep working on details in other programs.

FBX, OBJ are the most common formats shared by other 3D modelling software.