Strange behaviour with drawing an ellips

TNO · Unread post by **TNO** » Wed Mar 12, 2008 1:50 pm

Hello,

I've asked this question already in the past but I didn't get an answer so I will try it again.

Draw a horizontale line, with begin and endpoint snapping on grid.
Put a point on that curve and move it outside that line.
Try to draw an ellips with 2 focus points on begin and endpoint of the curve and passing point on the point which is already drawn in line with the curve.

Result -> not possible. Why?

Ok, turn off snapping and do exact thing described above.

Result -> ellips with focus points and passings point all inline of eachother.

Moving the passing point in second situation sometimes results in an invalid ellips, and sometimes the ellips turns arround it's axis.

Why this behavious, but more important: can it be fixed please

I've attached an example with 2 already drawn lines and 1 possible ellips.

jehronimo · Unread post by **jehronimo** » Wed Mar 12, 2008 2:12 pm

Hi,

it is surprising, because I tried on your top file, and I am not able to reproduce your problem...In fact I can, what I can not reproduce is your ellips!! I am not able to use your point and lines design to build an ellips!!

Maybe someone will help you, but for me it is correct to not be able to design an ellips with those constructive elements

I am using the v6.9.208...

Jehronimo

TNO · Unread post by **TNO** » Wed Mar 12, 2008 2:42 pm

The upper line won't be able to create an ellips.
However, the lower one is able to do so with 6.8.252

Remove the ellips, and make sure you draw a new ellips with option 'two focus'

If an upgrade of TopSolid makes the probem even worse, we won't update here soon I guess.
Here, again, it would be nice to see a changelog on the FTP server to see if those problems are finally solved.

TNO · Unread post by **TNO** » Wed Mar 12, 2008 3:00 pm

Other method to produce the same stange behaviour.

Draw a horizontale sketch line and place 3 points on that line.
Try to draw an ellips with those 3 points with left piont as left focus, middle point as right focus and right point as passing point.
Result -> not possible.

Go to your history tree and rotate the sketch line a few degrees and try the above again.
Result -> possible.
Let the ellips be there and try to rotate the sketchline back to 0 degrees.
Result -> invalid.

why?

example attached with ellips already drawn on rotated line (try to rotate it back to 0 degrees)