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Rotation clockwise seems negative

Started by donone, October 31, 2008, 09:46:20 AM

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donone

Using the dialog for rotation shows that rotating clockwise requires a negative number where I would have expected the opposite.
You only stop learning when you die.
Sometimes I think I am dead.

David

Yes you are right. This is a standard in mathematics, so we followed that.
Anti-clockwise rotations are positive.

David.
David Hoogvorst. Founder and Owner of DRail Software. Creator of AnyRail.

donone

Whilst I don't wish to create an argument or appear rude in any way (so please do not take any offence), you may well be right with electric motors and physics vectors but; the generally accepted practice in geometrical programs i.e. rotating photographs, objects in drawing programs and pages in word processors adding a positive number (45 degrees) to an existing position adds the number, thus rotating the object CW from say 0/360 to 45 ((360+45) mod 360) and similarly adding -90 degrees to 0/360 results in CCW rotation to 270 degrees.

Yes you have opted for one of the two choices as is your right, I am not saying you are wrong, I am simply saying it is not normal in these circumstances. Maybe there is a fine line between calling this a drawing program or CAD proper, that is outside my ability. I am only trying to be helpful in pointing out my observation that after many years of using such programs the unexpected happened.
You only stop learning when you die.
Sometimes I think I am dead.

David

Don't worry! Each and every comment is welcome! Our only goal is to improve the software and make it easier to use.

In this particular case:

I know it might seem a bit anti-intuitive, and indeed, one might argue about the exact sort of program this is.
What we do in these cases (as it is a Windows program for sure!), we try to follow whatever Microsoft does in their Office suite.
If you rotate a picture in Word or PowerPoint, it goes anti clockwise with a positive angle. So we simply followed that.

Hope this explains it a bit,

David.
David Hoogvorst. Founder and Owner of DRail Software. Creator of AnyRail.

donone

You are of course right David and I apologise.
A little more research confirmation in future (think twice speak once, comes to mind).
I always look upon zero at 12 o'clock and +90 deg as 3 o'clock, 270 as 9 o'clock.
I don't know what planet I have been on, but something is wrong in my mind. (And I haven't visited Australia!)
You only stop learning when you die.
Sometimes I think I am dead.