Hi ...

This one has me completely baffled.
First I made the smaller wineglass type object with a line of the profile and then 'revolved' it ... no problem.
Then I made the larger profile and revolved it to get a result like the one with the plane cut through it.
I erased it and switched to Rhino and used revolve to get the free standing oobject ...
then I switched back to MoI and tried again with the same profile ... only to get the cutting plane again.

The only difference I know of in approach is that with the first small object I create the profile and left it alone.
The larger one, I turned points on and manipulated it a little before doing the revolve.

I know my objects are very large ... the units are set to 'feet' I think ....

cheers,
eric

Odder and odder!

When I separated the plane from the glass - there were four planes?

Ray

Hi Eric, that certainly is weird!!

But it is definitely related to a control point edit - if you turn on control points for that curve, if you look in the lower right corner you can see a red square that actually shows up in the viewport:



Zooming in:




That red square is shown if you have some control points for the curve stacked up right on top of each other.

That kind of stacked up points tends to cause a problem with some of the geometry library functions that are used for determining insides and outsides of closed boundaries.

To fix it, zoom in to that area, and click and drag on that point that has the red box around it to move it slightly up and unstack those 2 points from each other so that they are distinct, then your revolve should work as you would expect.

I would like it if the geometry library was not so sensitive to stacked up points like this, but it will probably be a fairly difficult thing to make that happen anytime soon. So it is best to avoid that kind of point stacking, when you drag points and see that red box indicator, that means you have created some stacked points and you need to unstack them in that area.

- Michael

Thanks,

To be honest, I had not noticed the red box ... I'll know to look for it next time.

I fixed it and yes, 'revolve' worked fine.

I have been trying to get my head around 'loft, sweep and extrude', their differences and similarities and sure get some strange shapes I don't expect sometimes.

I'm used to working mostly with straight lined basic architectural stuff and those all seem to work for me as I expect.

Using MoI I have added some windows and doors to my 'parts' library.

Thanks
eric

Hi eric,

> I have been trying to get my head around 'loft, sweep and
> extrude', their differences and similarities and sure get some
> strange shapes I don't expect sometimes.

When you run across the strange ones, if you can post them here I could probably explain what is going wrong.

For sweep the main thing that can be confusing is whether "auto-place" mode is being used or not.

Auto-place mode lets you draw a sweep profile flat on the regular drawing plane, and then will move and rotate it into place perpendicular to the rail curve for you, before starting to drag the profile along the rail.

Auto-place mode is implicitly turned on or off depending on whether the profile curve is inside the bounding box around the rail curve or outside of that box.

So one thing that is easy to do is to draw a flat profile curve but not have it quite far enough off to the side so that it is outside of the rail's bounding box. That will mean auto-place will not be turned on, and your curve will be taken from exactly where it currently stands and then dragged along the rail curve.

I am planning on making some more explicit control over turning auto-place on or off which I think should help a bit.

That auto-place mode is also covered on that 6-legged pod video tutorial: http://moi3d.com/1.0/docs/pod.htm

- Michael