Cursor jumping erratically when trying to pick object snap point in 3D

Hi folks,

This had been driving me mad and I searched for ages but got nowhere. Basically my problem is as the title says. I am trying to made a 3D model of a building which contains 2D lines copied from plans/sections etc as templates for objects. For example, when I try to draw a polyline around some 2D lines which I would then add thickness and convert the resulting object to a solid.

It seems to snap to the correct points, right up until the cursor is almost on it, then it just jumps to the middle of nowhere.

I am using AutoCAD 2011. I have an ATI 1GB HD 4870 graphics card with an Intel i7 920 CPU so my PC should not be the problem. I have updated to the lastest graphics drivers. I have tried turning off and on hardware acceleration and the problem is still there.

'Snap Mode' is set off. It only seems to happen in 3D, drawing 2D is fine.

Any ideas?

Craig.

Edit - Oh yeah, it only seems to do it in some drawings that've been working on for a while before. Newer 3D drawings with 2D lines seem to be ok, no jumping (so far).

Have you downloaded and installed Update 1 for 2011?

Hi ReMark,

I didn't have the update installed, so I've just installed it but have still got the same problem. The snap is like to +ve magnets which repel each other. When ever the cursor gets close, it just shoots off to some random space.

Ive had that problem before, but I never really figured out what caused it, I think it had something to do with the Snap, try turning them all off, and just the one that you want.

If that doesn't help, then try setting all of the settings back to how they are when you first get AutoCAD.

1. Type Options

2. Then go to Profile Tab

3. Choose AutoCAD (or a different one if you want a different setup)

4. Choose Reset

5. Ok and exit Option dialog.

Best of Luck

Gir

Edit: Oh the view cube may be the source of your anguish, Please try to refrain from using that. In my experience it just makes things worse for everyone.

Try turning off your dynamic UCS. It's at the bottom of the window. The icon is a UCS icon with a lightning bolt. Also, turn off snap mode, which is right next to grid.

just a question cmwatt, why are you drawing around a 2D object with a polyline, ( nonononono ) have you try'd using REGION select the objects this will turn the lines etc into a solid face that you can extrude into a solid object using extrude or ALT and push pull command if you are using 2011 full

lemme know if that helped or maybe iam reading your post wrong ?

Hi ReMark,

 

I didn't have the update installed, so I've just installed it but have still got the same problem. The snap is like to +ve magnets which repel each other. When ever the cursor gets close, it just shoots off to some random space.

Have you answered your own question here?

You say that you have Snap Mode turned off, but what about the AUTOSNAP MAGNET? (Tools > Options > Drafting).

Thanks for you help guys, turns out it was the autosnap magnet in the options which I must have over-looked which was causing the problem.

As for the Region Command, it doesn't seem to work on some of the 2d lines, not sure why.

Craig.