Extrude an Image

In my recent pursuits of taking up 3D printing, I've found a desire to try to print an extruded version of an image.  The following is one approach to achieving this using Inkscape and Blender.  For this entry, we will use the blender logo.

The basic process is in converting the original image into an SVG and importing that SVG into Blender and then extruding that object. We will use Inkscape to convert a PNG into an SVG.  

Bevel Text

This entry will cover the function of adding a Bevel to the built in Text object as can be shown below.

Curve Handles

This entry covers the details of the types of Curve Handles.  The type of curve handle affects how the curve will be shaped with respect to the other handles.  There are four types, and we'll cover each of them and how they behave.

Before we begin, note that a single curve can have multiple curve points (hence multiple handles) and each curve point can have a different handle type.

The first handle we'll describe is the Free handle.  All curve points have three selectable points on them.  The center of the curve point, and the ends of the curve handles.  In the Free mode, the ends of the curve handles can be manipulated independent of each other.  This can product a sharp point at the curve point.

Mesh of a Curve

This entry will cover the function of both displaying the wireframe of a curve solid over the solid view.  This makes it easier to adjust the level of detail or resolution in the mesh of the curve.

For this example, we'll start with a curve solid that is generated by assigning a circle curve as the bevel to a the standard bezier curve.  Extrude along Curve

Instance Along Curve

This entry covers the concept of duplicating a mesh (cube in this example) along the path of a curve.  This is a very useful animation ability when trying to grow a curvey line or path.  

To start off you'll need at add [SHIFT+A] a curve and a mesh (cube).  It is worth noting that the direction of the curve matters for this example.  To have the cube follow the path of the curve directly, you'll want to situate it at the beginning (curve arrows are pointing away from cube) of the curve.

Curve Path

This entry will cover the use of a Curve called a Path, which can be used to guide an object to follow along its path.  A very obvious application for this is to create a roller coaster, which we will do for this example.

First add [SHIFT+A] a Path through the add Curve menu.  In Edit Mode [TAB], you can manipulate the curve by moving the control handles and extruding [E] points as necessary.  A vague idea of the shape of my coaster can be seen in the image below.

Next is the process of adding an object to follow the curve.  In this case I'll be using the Camera so that I can view a first person perspective of riding along the path.  Joining the two is done by parenting the object (i.e. Camera) to the curve, selecting both and [CTRL+P], and selecting Follow Path.

The time of the animation created by this can be controlled in the curve properties panel on the Path itself.  By default the animation length is 100 frames.

Note that the point at which the following object (camera) is attached to the curve will be based on the animation frame that is selected.  If frame 1 is selected, that will be connection reference point for the camera.

For fun, I created another curve in the shape of a slice of the track to give the track a physical presence.  The curve can be seen highlighted in the image below.

To apply it to the curve, select it in the Bevel Object box of the Geometry section in the Curve properties.

Finally, adding some support poles and a base floor, the track is complete, and the animation of the roller coaster can be run.  Note at certain curve points, the orientation of the following object may rotate, and so correction may be necessary with keyframes [I] on the following object.

Video of the roller coaster animation.

Sapling

This is a quick summary of the tutorial posted here: Sapling Tutorial that details how to generate trees using the internal add-on Sapling.

So first enable the add-on.  If it's not available in your menu, you'll need a newer version of Blender.

Once the add-on is enabled, you can add a Tree in the Curve menu.

At first the tree won't look like much, so make these initial setting changes in the tool-panel [T] (on the left).

Now we have something that looks like a tree.

Note that there are numerous settings in the Sapling add-on by which you can tailor your tree.  Only the basic major settings will be covered here.

To generate a new tier of branches increase the Level.
To move the branches up and down the trunk, adjust the Base Size.

New tree with Level 3 branches and lower base.

Next, adjust the Vertical Attraction to give it a perky, or willow like feel.

Notice with a negative Vertical Attraction, the branches hang down.

Finally, show the leaves.  Rectangular leaves use less computing power.  You'll want to use textures to define the leave shape anyway.

Fully developed tree.

Note that the tree is composed of a curve which is the trunk, and a mesh which represents the leaves.
This allows for easy texturing of each component individually.

A simple render of a brown trunk, and green leaves.

Extrude Along a Curve

This entry covers the topic of creating curves with body, or more simply cables.  In this example I'll make a round cable, but any shape (that is a curve) can be used.

In the viewport I have two curves, one is a circle, which I'll call CableWidth, and another curve which is just a arbitrary shaped curve which I'll call CablePath.

What we want to do is give our CablePath some body in the shape of the CableWidth.

First the circle (or CableWidth) must be a curve.  If it is a mesh, use [Alt + c] to convert it to a curve.

Next, select the CablePath, and on its Curve tab, set the Bevel Object to the CableWidth.

The CablePath should now have shape, and you can adjust the shape by adjusting the CableWidth.