curve for points

[_Vale_]

Good evening, everyone. I am new to the forum and I would have a question maybe banal for many of you. I will try to be brief: I have a plan of construction of a hull (only transversal) in pdf. I cut it and saved it as jpeg and opened it as a background bitmap. I then began to recalculate the curves with the "curva per punti" command. I don't know what I did, but with the same command, I don't get the results before. If I click on the background curve, the point is not placed where I indicated but in a different position. the curve obtained therefore no longer follows the "original" that I have to recalculate but does of the ondines, more or less accentuated depending on the degree given in the settings of the curve. the same thing happens using the "interpolated curve" command though in the instructions, the short film shown, shows a different result. What I'd like to get!
I certainly changed some setting that I didn't have to touch!
I hope to receive some indication from you who know how to use it! !
Thank you

 

[guyver]

I didn't understand your problem well.. .
so on the fly..
Did you accidentally press f9 grill snap?

 

[_Vale_]

No, I didn't press f9...
in practice until last night I built the curves by hand in the points I was interested in and the curve almost precisely recalculates the background image.
Now instead when, after clicking to fix a point, I move it is as if rhino continued the curve so as to make it tangent to the lines of the grid...probably it is a "block of the direction"...the problem is that I use it alone a week and I have no idea how to remove it!

 

[uluwatu_74]

maybe you used "distractably" command 1...while what you would like to use and that you used previously is command 2.

 

[_Vale_]

no, I didn't have wrong command... I pressed the tab key (director lock, f8). Now I've solved!
thanks to guyver...I took inspiration from his answer to find the solution to the problem!
good work to all and thanks for availability!