Theme

The working plane

Which surface a click lands on when you are in 3D.

A click on the screen is two numbers, and a point in the model is three. The working plane is what makes up the difference: it is the flat surface your clicks land on.

In PLAN there is nothing to think about - everything lands on the floor. In a 3D view it matters, and this is the thing that catches people out.

By default it follows the face under the cursor

Point at the top of a box and draw, and the shape lands on the top of the box. Point at the side, and it lands on the side. Most of the time that is right and you never notice it.

The same rectangle tool used twice with nothing changed between: the first rectangle lies flat on the top of the box, the second stands upright on its side.
The same tool, twice, with nothing changed in between - one rectangle lies flat on the top, the next stands upright on the side. The only difference is which face the cursor was over when it started. Watch the PLANE reading in the top right change with it.

Locking it

The one that bites

A shape drawn across a face has to stay on that face, or the loop never closes and no face is made. If a shape you drew in 3D refuses to fill in, that is almost always why: one point wandered off the plane. Lock the plane first and every point of the shape is held to it.

Once a line is under way the arrows stop picking the plane and start locking a direction instead, which is what they are for at that point.

Or just work flat

Draw it in PLAN, where there is no question, then push it up. That is the short way round most of the time, and it is why PLAN and push/pull between them cover so much.

See also