DocsHow-to

Make shapes

Everything starts as a shape. A crate, a pillar, a shield, a bottle. The useful surprise is that there are far fewer shapes than there look, because most of what you want is one shape with different numbers rather than a different shape altogether.

When you need this you are starting something new and need geometry on screen.

A shape is its numbers#

A cylinder with Radial Segments at four is a box. With three, a wedge. Take its Top to nothing and it is a cone, or a pyramid if you left Radial Segments at four. None of those are separate nodes. They are one node with the numbers moved.

This matters more than it sounds. If you reach for a pyramid node and cannot find one, you will conclude the app cannot make pyramids. What is actually true is that the pyramid is where the cone already was.

Radial Segments at 4 is a box, at 3 a wedge. Top Radius at zero is a cone, or a pyramid if the segments are low.

So when a shape is nearly right, look at its numbers before you look for another node.

Sizes are in metres#

One unit is one metre, and staying near real sizes keeps everything else working. A prop lands somewhere between 0.2 and 3, a person around 1.8, a scene under about 40 across.

The figure is 1.8 metres tall. A crate near one metre reads right beside it.

Very small models cause trouble that does not look like a size problem: the operations that weld, cut and merge compare real distances, so a model built at a hundredth of normal has its detail collapse into itself.

Outlines, when a primitive will not do#

Some shapes are a flat outline with thickness. Shields, signs, door plates, window frames. The Shape node draws one from a list of ten silhouettes and extrudes it, and it can punch a hole in the same move, using the same ten.

One node draws the outline and cuts the hole in the same move.

That is one node for a thing that would otherwise be a cut, a bevel and a lot of care.

Outlines, spun#

Anything round and symmetrical is a drawn profile spun about the middle. Bottles, goblets, pillars, finials, wheels. Draw the silhouette as a handful of Curve Path points, hand it to Lathe, and it sweeps it into a solid.

The knob worth knowing is Phi Length, how far it spins. Less than the whole way round gives you a cutaway, which is useful for showing an interior and for making half-round mouldings.

The silhouette is four points. Spin it less than the whole way round for a cutaway.

Put it on the ground#

A shape is built around its own middle, so half of it starts below the floor.

Place On with nothing wired into its Base moves a shape so its underside sits at zero. It measures the shape each time, so it stays correct when the knobs change, which a typed offset does not.

One Height knob drives both. The left cylinder grows around its middle; Place On keeps the right one standing on the floor.

If your shape was already drawn from the ground up, as a spun profile usually is, you do not need it at all.

Open the editor and try it