Changing arc direction?

[pkelecy]

This is a simple (but annoying) thing. Sometimes when drawing a centerpoint-arc, the arc tool will try to draw the arc in the opposite direction from what I want. For example, after selecting the centerpoint and starting point, if I then move the cursor counter-clockwise, the arc will sometimes go clockwise instead! I've seen this happen with arc tools in other CAD programs as well (must be something in the tool algorithm that causes this). Is there some way (a key press or other) to make it reverse direction when this happens?

Thanks, -Pat

 

[donyoung]

I think it was the ALT key to be pressed while doing the arc
then it will obey your intention ;-)

dy

 

[pkelecy]

Thanks dy. I tried you're suggestion, and it wasn't clear to me that is worked. However, I was having trouble getting it to misbehave, so I'm not sure. I guess I'll have to wait until I encounter the problem for real to find out. :^)

Pat

 

[Raaden]

The reason why the arc behaves like this has to do with Intellisketch (how I don't really know)
What holding the ALT key does is that it disables Intellisketch, thus making arcdirecting a lot less frustrating.

 

[pkelecy]

Thanks Raaden. I wasn't aware of that about the Alt key, but that's good know (beyond just this issue).

Pat

 

[beachcomber]

I can't get this behaviour on V19 - the arc goes whichever direction I indicate, even if I enter the rad & angle before placing.
Can anyone identify the conditions that cause the effect?

bc.
2.4GHz Core2 Quad, 4GB RAM,
Quadro FX4600.

 

[Raaden]

Well if place the starting point of the arc in the "air" then it behaves just like you want it to do, but if your starting point is placed at the end point of a line then the weird stuff start to happen.

I have everything except Pierce point and Extensions checked in Intellisketch

 

[beachcomber]

Just tried this on V19 - it appears to be dependant on where
you put the cursor CENTRE.
I created a line and placed an arc by centre, with the centre at the left end of the line.
Now move the cursor to the right end of the line.
The cursor has a circle on the cross - this is the INTENT ZONE (which can be adjusted in size).
Place the intent zone over the end keypoint but with the cross just above the line and the arc will be drawn inti-clockwise.
If you have the cross below the line the arc will gou clockwise.
So it looks like it works as designed - the position of the cross determineswhich way it is drawn.
In 10 years I'd never noticed this!

bc.
2.4GHz Core2 Quad, 4GB RAM,
Quadro FX4600.

 

[pkelecy]

Yes, this is where I've been seeing this also. It's where the first point is locked to a keypoint on another sketch entity that things can behave weirdly.

bc - I see what you're saying. The arc will draw from the same side you approach from. What's also interesting is if you move to the other side of the start point afterward, it will continue to draw in the same direction (making almost a 360° loop).

I think this behavior (if by design) is maybe more useful for the other arc tools. For a center-point arc, it's not particularly intuitive, and if you decide you want the arc to switch directions, you basically have to start over (as far as I can tell). I'd prefer to see it operate the same as when drawing in free space.

Pat

 

[beachcomber]

Pat,
"I'd prefer to see it operate the same as when drawing in free space"...
This would require an extra click to indicate the arc direction, but as you say it would be more intuitive.
As it stands the second click indicates radius point AND direction even though the distance is very small.
Now I know how it behaves I won't get it wrong so often - hopefully!!

bc.
2.4GHz Core2 Quad, 4GB RAM,
Quadro FX4600.