« on: October 27, 2014, 09:42:00 PM »
Hi Frank, to get a point-to-point measurement you need to change the Type to the one in the bottom-left of the flyout, that has two circles and a blue line with dots on either end. The Direction setting will be ignored for this type of measurement.
You are right, it is not really possible to know which are the X and Z axes (Y is up). If you have the grid on, it will show you the two directions, but you will have to check both to find out which is X.
Since it doesn't exist in any documentation, I will just explain the other Types:
First row, left-to-right
- interior measurement from left-click-point to first ray intersection (ie ray goes into surface)
- exterior measurement from left-click-point to first ray intersection (ray goes out from surface)
- interior measurement from left-click-point to last ray interesection (ray into)
- exterior measurement from left-click-point to last ray intersection (ray out from)
- point-to-point (left-click to right-click points. In 123D navigation mode, use ctrl-click/cmd-click instead of right-click)
- absolute 3D coordinate measurement
- cylinder measurement (this is pretty flaky...but draw with left mouse to drop sample points, and eventually it will fit a cylinder and show you the radius)
For the modes above that mention a ray-cast (ie the top row), the Direction field defines if the ray direction is the Surface Normal, or one of the X/Y/Z axes.
The three numbers on the right are the Current measurement under the cursor (middle, black), the Maximum value measured during a click-drag operation (top, grey) and the Minimum value (bottom, grey). This range is useful if you are taking measurements from scan data, where (for example) thickness will vary over an area.