Blender and Bézier Curves
for
3D Printing
Vicky Somma
@TGAW
http://www.tgaw.com

About Me
● Lead Software Developer for Food Safety
Labs
● Mother of two boys (seven and five)
● Started 3D Modeling and printing designs
with Shapeways in February 2014
● Won the White House 3D Printed Ornament
Contest in December 2014
● Got my first 3D Printer in March 2015
● Published a book on 3D Modeling in 2017
Two takeaways:
● You don’t have to apply yourself full time to learn 3D Modeling.
● You don’t need a 3D printer to get started 3D Printing.

3D Printing Requires a 3D Model
3D Model -> Slicer -> Print

About Blender
Expansive, free, open-source software for:
● 3D modeling
● Rendering
● Rigging and animation
● Game engine
● Video editing
Interface can be overwhelming with lots to learn, but HUGE community behind it
with lots and lots of tutorials and videos.
https://blender.org

Blender - Windows and Screens
● Info View (Menu)
● 3D View
○ Tool Shelf
○ Properties Shelf
● Outliner (List of
Objects)
● Properties
Reference: https://docs.blender.org/manual/en/latest/interface/window_system/introduction.html

3D View - Navigating
Rotate View Pan View Zoom In Zoom Out
Mouse scroll wheel helps you view your work from all angles and distances
No Mouse? http://www.blenderhut.com/use-blender-without-middle-mouse-button-or-scroll-wheel/

3D View - Navigating
View menu at the bottom of the 3D View has
shortcuts to specific perspectives:
● Left
● Right
● Back
● Front
● Bottom
● Top

3D View - Selecting Objects
Left Click for Actions
Scaling, Rotating, Moving (including "Moving 3D
Cursor")
Right Click for Selections
Selecting Object, Vertex, Control Point, etc
Screenshot from Blender 3D Printing by Example

Vertices, Edges, Faces
The 3D models you make in any software will be comprised of:
● Vertices
● Edges
● Faces
Reference: https://www.mathopenref.com/edge.html

3D View - Object Interaction Mode
Menu at the bottom of 3D View (or Tab)
lets you change how you are interacting
with your objects.
● Object Mode
Actions for an entire object such as
Add, Delete, Scale, Rotate, Move
● Edit Mode
Edit specific details of an object-- even
down to vertex level.
● Sculpt Mode, Texture Paint

Blender - First Project
Each project starts with three default items:
Screenshot from Blender 3D Printing by Example

Blender - Deleting Default Cube
1. Make sure you are in Object Mode
2. Right click to select Cube
3. Hit Delete key and confirm.
Screenshot from Blender 3D Printing by Example

Bézier Curves
● Mathematically defined
curves based off of “control
points” and “handles”
● Not specific to Blender--
used in computer graphics,
fonts (PostScript, TrueType),
animations
● Developed to draw smooth
curves for automobiles
Reference: http://mathfaculty.fullerton.edu/mathews/n2003/BezierCurveMod.html

Why Start with Bézier Curves?
● Streamline making complex shapes, particularly
flat ones.
● You aren’t defining every vertex. You’re
defining curves (which Blender will turn to
vertices later)
● Bézier Curves can also be used make 3D
objects (Like the Cancer Ribbon)
● Once you master Bézier Curves, you can use
them to add bends and curves to other objects.
● Bézier Curves knowledge translates to adding
text and importing in outside logos.

Making It Easier with a Background Image
When learning to write, we start with
tracing.
We can add a background image in
Blender to trace without a steady
hand!

Pulling in a Background Image
1. Click on the + or hit N to open
Properties Shelf
2. Check Background Images
3. Click Open

Pulling in a Background Image
4. Browse to and pick image
5. Click Open Image

Viewing Your Background Image
Upper Left corner of 3D View shows how
you are looking at your object.
By default, your background image is
going to be visible in the Top / Ortho view.

Perspective versus Ortho
We are looking at 3D objects on a 2D screen.
● Perspective View adjusts proportion to
account for depth (like foreshortening a road
to a horizon)
● Orthographic View keeps sizes intact
regardless of depth (parallel lines) are
parallel.
Perspective is subject to optical illusions.

Viewing Your Background Image
View->Top and then View->View Persp/Ortho
Drone Credit: https://www.istockphoto.com/vector/drone-vector-gm604383194-103803029

3D Cursor
Where new objects are going to be added
Can also be used for rotation, scaling and tweaking object’s origin
points.
Moving it is as action, so you move it with a left click

Add a Bézier Curve
1. Make sure you are in
Object Mode
2. Left click to place 3D
Cursor where you want
to start
3. In Toolshelf, go to
Create tab and under
Curves pick Bezier

Control Points and Handles
Switch to Edit Mode to change the look of
the curve.
● Control Points
The start point and end point of the
curve.
● Handles
Controls the impact and the shape of
the curve, how it gets to its destination.

Moving a Control Point
1. Right click to select the point.
2. Left click in the white circle to drag or drop or left click on the arrows
(Shortcut key G for grab).

Axis Arrow Cheat Sheet
● Red - X axis
● Green - Y axis
● Blue - Z axis

Adjusting Handles
● Right click to select the handle
● Left click to drag and drop.

Adding New Control Points
● Right click on the Control
Point you want to grow from
(that'll be the new starting
point) to select it
● Control Left Click on where
you want the new end point.
Control-Z to Undo any mistakes

Changing Handle Type for Sharp Corners
By default all your handles are "Auto" which keeps the curve as smooth as
possible. For sharp corners, you don't want a smooth curve.
● Right click to select the
Control Point
● In Toolshelf pick the
Tools tab and under
Curve Tools->Handles
click Free

Finishing and Reviewing Work
Alt-C for “Cyclic” mode, aka
close the curve
Reviewing Work
1. Switch to Object Mode
2. Hide background
image if necessary.

Converting Curves to Mesh
Curves have Control Points and
Handles. We want a Mesh with
Vertices, Edges, and Faces
1. Make sure you are in Object Mode
2. Right click to select curve
3. Object->Convert To->Mesh from
Curve/Meta/Surf Text

Converting Curves to Mesh
Once a mesh, our Control Points and Handles are gone. We have Vertices!

Making a Face - Selecting All Vertices
1. Make sure you are in Edit Mode
2. Select->(De)Select All or hit A to
select all.

Making a Face - Create Face
1. Mesh->Face->Make Edge/Face (or
hit F)

Making a Face - Face versus Fill
Make Edge/Face will make a single face and will fill any foles.
Fill (Alt-F) will make a series of faces and will work around holes.

Sizing and Design Requirements
● With 3D Printing, think in millimeters
● What are you making?
● What are the size limitations of the printer?
○ Innovation Lab T-shirt Printer- 12" (304.8mm x
304.8mm)
● What are the size limitations of YOU?
○ A shirt on me would be more like 8” by 10” (203.2mm
x254mm)

Reading and Setting Sizes in Blender
Dimensions and Scale
visible in the Properties
Shelf.
Treat default “Blender Units”
as millimeters.

● Type in exact Dimensions and match Scale to keep proportions.
● Or Object->Transform->Scale (S) to Scale with the mouse.
Reading and Setting Sizes in Blender

Turning 2D to 3D with Extrude
Our single Face has no thickness. The printer would have nothing to print.

Turning 2D to 3D with Extrude
1. Switch to Edit Mode
2. Switch to Face Select Mode
3. Right click to select Face.
4. In Toolshelf, under the Tools
tab click on Extrude>Extrude
Region
5. Type in exact height (0.5mm)
or use mouse to size.

Turning 2D to 3D with Extrude
Your 2D shape now has a thickness and is a full 3D mesh.

Exporting to STL
STL is a file format compatible with the printer’s slicer.
1. Right click on what you want to
export to Select
2. In the top menu, go to
File->Export->Stl (.stl)

Exporting to STL
STL is a file format compatible with the printer’s slicer.
3. Check Selection only
4. Pick a file name and hit
Export STL

Using Scalable Vector Graphics Files
Blender has the ability to import in SVG files.
SVG files can be found at:
● Online repositories
● Graphics departments
NOVAGraphics@nvcc.edu
● Make your own
Inkscape, PhotoShop
https://www.nvcc.edu/mascot/_docs/NOVA-Mascot-Logo%20Guidelines082316.pdf

Using Scalable Vector Graphics Files
1. Start a new project
2. Delete the Default Cube
3. Go to File->Import and pick
Scalable Vector Graphics (.svg)

Using Scalable Vector Graphics Files
Does it look like nothing
happened?
Your SVG file may be there, just
really, really little!

Using Scalable Vector Graphics Files
SVG files import in as… Curves!
You can make adjustments to
Control Points and Handles.
Like before, we’ll need to:
● Convert to Mesh
● Scale to proper size
● Extrude to give it height
● Export STL

Adding Text
Text is an easy way to personalize something and make it your
own.
1. Make sure you are in Object Mode
2. Left click to move the 3D Cursor where you want the text
3. In the Toolshelf, go to the Create tab and click Text under
Other

Adding Text - Sizing
Text will be “Text” at first. It may be hard to see. Multiple ways
to make it bigger.
1) Hit S and using the mouse to scale.
2) Typing in a Scale in the Properties Shelf

Adding Text - Sizing
3) Adjust the Font properties in the Properties Window!
a) Right click on Object to select it.
b) Click on the F icon in the
Properties window
c) Increase the Size under the Font
section.
Note: These same Font properties can adjust the Font
face and spacing between words and characters.

Adding Text - Customizing
Changing the text changes the “shape”.
1. Switch to Edit Mode
2. The cursor is placed at the end of the
text.
3. Backspace 4 times and type what
you want.

Adding Text - Making It 3D
Same steps as Bezier Curves.
1. Object->Convert to->Mesh
From Curve/Meta/Surf/Text
2. Switch to Edit Mode
3. A for Select All
4. E for Extrude and type
thickness

Working with Multiple Objects - Lining Up
Switching your view may reveal alignment flaws.

Working with Multiple Objects - Lining Up
Each Object has a yellow Origin
Point. The Location in the
Properties Shelf lists the exact
coordinates of that point.

Working with Multiple Objects - Lining Up
Each Object has a yellow Origin
Point. The Location in the
Properties Shelf lists the exact
coordinates of that point.

Working with Multiple Objects - Selecting
Multiple Objects can be selected with Shift-right click.

Working with Multiple Objects - Selecting
Multiple Objects can be also selected with Select->Border Select (or hit B).
Left click and drag a square around what you want to select.

Working with Multiple Objects - Exporting
With both items selected, they will both be included in a single STL file when
you export with Selection Only

Blender - Learning More
● Books
Such as Blender 3D Printing by Example
● Tutorials & Blogs
https://www.blender.org/support/tutorials/
● YouTube
Joe Larson (3D Printing Professor)
If you see the name “Jonathan Williamson”, it is going to be a great tutorial.

Blender Not For You?
There are lots of other modeling options
(free and paid) out there. Shapeways has a
compiled a great list of options at
https://www.shapeways.com/creator/tools

Vicky Somma vicky@tgaw.com