We continued with our tank. In this session we:

1. Used an array to generate multiple track segments (treads)
2. Uses a curve modifier to fit these around our curve
3. Used a negative scale to mirror some objects
4. Created a simple terrain with a cloud texture and a displace modifier
5. Generated a procedural texture for generating camouflage

Which was a lot!

Here are the video notes:

The updated tank model can be found here.

This week we continued with our tank model.

We created a set of wheels from a cylinder which we then scaled, duplicated and used inset and extrude to provide a little detail on each wheel.

We then created a bezier curve to define the shape of the track across then wheels. Bezier curves are an easy way to defined a smooth shape. They have a number of points through which the curve passes. Each point has a pair of handles. The rotation of these handles defines the angle at which the curve passes through the point. The distance between the handles defines how tightly the curve bends as it approaches the point.

Here are the video instructions for this week:

The updated tank model can be found here.

This week, we finished our apple project started in week 12. We took the images we’d made and stencil painted them onto our apple model.

Here are the video instructions for the stencil painting:

The completed apple model can be found here.

Once we finished the apple, we started to talk about animation. To illustrate this, we started building a little multi-object tank model that we can later animate. Here are the instructions on starting the tank model:

The in-progress tank model can be found here.

This week we had a 3D printer in the room, so our plans to stencil paint the apple took a back seat until next week. Instead we printed a dice model and then looked at how to build that model.

The printer we used is a Prusa i3 Mk 2.5. To print a model you import it into a program called a slicer which converts it from a polygon based model into instructions for the printer in how to lay down a series of layers of plastic to build the same approximate shape.

The model we printed was a dice. To do this we used ‘hard surface modelling’ techniques, specifically the use of boolean operators. Boolean operators allow you to take two shapes and make a composite shape that is:

1. Difference: The first shape with the second cut-out
2. Union: A shape which is the two shape fused together
3. Intersect: A shape which is only where the two original shapes overlapped

This technique is powerful, but it results in many N-gons (polygons with more than four sides). N-gons are bad in many circumstances. For example severe distortion may result if :

1. If we try to apply smooth shading
2. If we try to apply a subsurface modifier
3. We later try to distort the mesh, as with an animation
4. If we export the model for use in other 3D packages

If none of those apply, hard surface modelling can have its uses.

Here is the instruction video for this week:

The dice model file can be found here.