anyone please help, I'm trying to construct circle from scan minimum, and in the search setup dialog, it asks for circle start point. what is this asking to enter exactly? Thanks so much!
The tricky part of doing that construction is getting all the inputs right.
First, select the right workplane. This is a 2D feature, so make sure the workplane makes sense in the same way as it would for a regular circle construction. You may need to make a local rotation alignment if you scan is not parallel to an axis.
Enter the coordinates for where you want the circle to start and approach the scan. Imagine dropping a steel ball onto/into the part. Where could you start the ball drop so that it lands in the low spot? Enter the coordinates as if you were teleporting the ball to that location. Make this start point a good distance away from the part so the ball doesn't substantiate in solid matter. Ignore the fact that the ball would instead substantiate in air, which is another form of matter, but probably still not good to teleport into. Sorry if that explanation got too Sci-fi, but I couldn't think of a better way to explain that.
Enter the Down Direction vector. This vector should be in the search direction, toward the scan. This can be easy if you just want to search down in the Z axis (0,0,-1), but if you want to search at an angle you may need to do a bit of trig to get the right numbers. A shortcut, if you have a CAD model, is to open the Auto vector point dialog box and click on the area where you expect the low spot to be. The vector of that point will be normal to that surface which is the opposite direction you need for down direction of your circle construction. If you take those IJK values and flip the signs, it will give you the vector you need.
Click OK, then Create, and wait for an error message. If you get one, keep messing with the input values. It may seem silly to add this as a step, but I often enter something wrong on the first try when doing this construction.
Look at the circle in the graphics display window. Make sure everything looks right.
