Hi.
I'm having som wonky behaviour with trimming. In the attached model I have a shelled surface and two trim planes.
But I can't trim the brep. It works sometimes, but mostly the whole brep is just removed. Ie trying to do the same trim several times, yield different behaviour.
Same issue on both desktop and laptop PC and both Moi 3.0 and latest 4.0 beta. Trim works fine in Rhino.

Bests,
Morten

Make a Boolean Diff better on solid objects
In fact your right object is not a simple surface but a Surface + a Closed Curve so problem!

Kill the Closed Curve first and all will works fine 3 Solids as result!
And in your special case make One by One!

Hi Morten, the problem is likely related to your objects being located a vast distance away from the origin, they're at around x = -650000 units. That can cause precision problems with floating point arithmetic.

If you move your objects to the origin it should behave better. You can do that by selecting it all, then run Transform > Move. At the first prompt for picking the base point for the move click the "Bounding box center" button, and then at the second prompt for picking the target point type 0 and push enter to move it to the 0,0,0 origin point.

If you do that you should then get better behavior from Trim. But also as Pilou mentions usually when you're cutting a solid you want to use boolean difference instead of Trim because Trim will just cut up the surfaces leaving a non-solid surface result while a boolean will keep the pieces of the cutting objects embedded in the results so it will be a solid result.

- Michael

Hi both.
While I'm aware the curve shouldn't be used as trim object, I didn't know distance to 0 was an issue in that range.
I'm used to having issues like that in Softimage, but because Rhino worked, I just assumed Moi would too!
I did try boolean as well, but it din't work for same reasons. Moving to 0 all is good now, thank you :)

M

<< the curve shouldn't be used as trim object
if you select both triming objet(s) + it's curves = problem but alone no problem !

In normal way Curve(s) can also be used as "cutting knife" solid! ;)