yasin2ray Posted March 8, 2022 Share Posted March 8, 2022 Why?! Why does a positive number rotate counter-clockwise and a negative number rotate clockwise? Quote Link to comment
0 markdd Posted March 8, 2022 Share Posted March 8, 2022 I think it’s the method that all CAD programs use. It’s to do with mathematics and the Polar coordinates system which always go counter-clockwise. I am sure someone else will be able to elaborate with a more academic explanation but I accepted it long ago and have got used to it! 3 Quote Link to comment
0 Andy Broomell Posted March 8, 2022 Share Posted March 8, 2022 Like Mark said it's based on Polar Coordinates, with 0° equating to the positive X axis. If you look at the 30° line in the graphic above you can start to see why positive values correlate to moving "counter-clockwise." It helps to picture this chart rather than a clock when thinking about rotation. 4 Quote Link to comment
0 yasin2ray Posted March 8, 2022 Author Share Posted March 8, 2022 24 minutes ago, Andy Broomell said: Like Mark said it's based on Polar Coordinates, with 0° equating to the positive X axis. If you look at the 30° line in the graphic above you can start to see why positive values correlate to moving "counter-clockwise." It helps to picture this chart rather than a clock when thinking about rotation. Hmm! Okay, thank you! I bet I haven't thought about that since high school. Quote Link to comment
0 line-weight Posted March 9, 2022 Share Posted March 9, 2022 14 hours ago, Andy Broomell said: Like Mark said it's based on Polar Coordinates, with 0° equating to the positive X axis. If you look at the 30° line in the graphic above you can start to see why positive values correlate to moving "counter-clockwise." It helps to picture this chart rather than a clock when thinking about rotation. It seems like mathematicians just being awkward by adopting a convention that is different from the one we all know from a compass. Quote Link to comment
0 Benson Shaw Posted March 10, 2022 Share Posted March 10, 2022 But vwx is inconsistent with rotational direction: I think i found another reversed rotation in a different tool cant find it. I think counter clockwise should be positive rotation. If new tools or nodes break existing , then just add a new “corrected” tool or node? -B Quote Link to comment
0 Jeff Prince Posted March 10, 2022 Share Posted March 10, 2022 18 hours ago, line-weight said: It seems like mathematicians just being awkward by adopting a convention that is different from the one we all know from a compass. but what if you are calculation angle of elevation from horizon? Doesn’t the positive x axis being 0 degrees make perfect sense? Putting it all into perspective, we need both azimuth and elevation conventions for angular measure 😉 1 Quote Link to comment
0 line-weight Posted March 10, 2022 Share Posted March 10, 2022 5 hours ago, jeff prince said: but what if you are calculation angle of elevation from horizon? Doesn’t the positive x axis being 0 degrees make perfect sense? Putting it all into perspective, we need both azimuth and elevation conventions for angular measure 😉 Well, the horizon is a very slight curve, whereas a plumb line is straight. If we are calculating an angle relative to the horizon, what we are really calculating is angle relative to a line perpendicular to the direction of gravity/a plumb line. Therefore I'm going to argue that taking vertical as our 0 degrees reference makes more sense - and it also corresponds with what most people are used to; compass directions. 1 Quote Link to comment
0 Jeff Prince Posted March 10, 2022 Share Posted March 10, 2022 2 hours ago, line-weight said: Well, the horizon is a very slight curve, whereas a plumb line is straight. If we are calculating an angle relative to the horizon, what we are really calculating is angle relative to a line perpendicular to the direction of gravity/a plumb line. Therefore I'm going to argue that taking vertical as our 0 degrees reference makes more sense - and it also corresponds with what most people are used to; compass directions. Architects vs astronomers 🙂 2 Quote Link to comment
0 FlyingHoward Posted March 10, 2022 Share Posted March 10, 2022 This is very educational for me, thank you to all contributors. For me, this "reversal" seemed to happen a SP or two ago where a Rotate 45 caused a Counter-Clockwise rotation. While I figured it was a bug, I know know why this happens and have since gotten used to it. Thanks again. Quote Link to comment
0 markdd Posted March 10, 2022 Share Posted March 10, 2022 19 minutes ago, FlyingHoward said: For me, this "reversal" seemed to happen a SP or two ago where a Rotate 45 caused a Counter-Clockwise rotation. This has always been the way things have worked in both Vectorworks and AutCAD. It is a CAD convention which is just one of those things. As I said above, it is something you just get used to over time and I rarely find it a problem anymore. Here is the source of your pain! https://en.wikipedia.org/wiki/Polar_coordinate_system 1 Quote Link to comment
0 LarryO Posted August 11, 2022 Share Posted August 11, 2022 (edited) Then I would ask why the menu icon representing the rotation tool shows the arrow in a clockwise direction? That would imply that a positive entry would rotate the object clockwise. 🤷♂️🤣😂🤣 Edited August 11, 2022 by LarryO 1 Quote Link to comment
0 yasin2ray Posted August 23, 2022 Author Share Posted August 23, 2022 On 8/11/2022 at 4:27 PM, LarryO said: Then I would ask why the menu icon representing the rotation tool shows the arrow in a clockwise direction? That would imply that a positive entry would rotate the object clockwise. 🤷♂️🤣😂🤣 THIS. As well, the description of the Rotate Tool should say something about polar coordinate rotation. Quote Link to comment
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yasin2ray
Why?!
Why does a positive number rotate counter-clockwise and a negative number rotate clockwise?
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