# Cursor constraint typed entry does not work

Angle constraint

Locks the next point will be placed at a specified angle relative to the last point.

To constrain to an angle
4 Type an angle at the command prompt in the format <angle and press Enter.

The cursor moves along a line at the specified angle.

NO IT DOESNT. well not for me anyway.

I select line tool, click start point, then type <47.457 and hit enter, draw the line in a north west direction which appears at that sort of angle (as rhino 0 is north) yet measure it afterwards at it isnt !.

have I overlooked something ?

it also will draw two other lines near vert and near horiz neither of which are 47.457 on anything.
Angle constraint fail.3dm (31.0 KB)
Steve

that may help to understand

Rhino ANGLE Zero is actually “East”… It starts along the X axis and rotates CCW with positive angles (right handed mathematical coordinate system).

–Mitch

Nope- zero is East, as is pretty standard I think.

-Pascal

Hi, I guess my school protractor is to blame, it had 0 straight up and went round to 90 both CCW and CW.

Macromdeia Freehand when entering constrain 47 drew a line north west 47 deg to vert or horiz, one of the two.

Just tried it but no degree measuring tool to establish hrz or vert. Gosh how did I manage with no angle measuring device ?

On an RAF compass 0 was straight up.

bandits angels 15 vector 045 was north east !

I have always thought of up as base point.

why when it is natural to do so was east chosen ?

is there an option for altering base to north. I see there is in another cad prog.

Steve

From Wikipedia:

In a two-dimensional Cartesian coordinate system, an angle is typically defined by its two sides, with its vertex at the origin. The initial side is on the positive x-axis, while the other side or terminal side is defined by the measure from the initial side in radians, degrees, or turns. With positive angles representing rotations toward the positive y-axis and negative angles representing rotations toward the negative y-axis. When Cartesian coordinates are represented by standard position, defined by the x-axis rightward and the y-axis upward, positive rotations are anticlockwise and negative rotations are clockwise.