Hi.

I tried to achieve a perfectly smooth surface like from a pebble or cabochon
with rail revolve and network but did not succeed. So my question to you
dear Moisters is if there is a way to get that nice homogeneous shape ?

Hello Tom,

here a some examples:


For railrevolve take care, that the tangents of the profile are perpendicular to the rotation axis.
I hope that helps!

Have a nice day
Karsten

Hi Tom, I'd probably try using Loft with the "Loose" option with horizontal sections ending in a point, like this:
http://moi3d.com/forum/index.php?webtag=MOI&msg=8302.4

- Michael

Hi Karsten thank you for the helpful + instructive file - great ! And David for the link !
Will go through the techniques explained and am sure it will lead to
the smoothest pebbles ever ;-)

Michael, i think i asked awhile back but forgot.

Is there a way for you to look at the spheres points "transforming" after a certain level of manipulation and forcing it to remain? (It transforms into another type of analytical object or something)

Maybe the new geometry library can provide it...

Hi Burr, sorry I'm not really understanding this. What type of analytic surface do you want to get after editing some sphere points?

When you edit the points of a sphere, the original exact sphere is actually replaced by an approximation. That's because the actual exact sphere's control points are not good to squish around because an exact NURBS sphere has "fully multiple knots" (basically corner points) which will form a crease if you move them around individually.

- Michael

Hi michael,
I'm not looking for a transform. Here's the jist.

I can create a sphere and turn on points and manipulate. (Keeping that initial "round sphere cage" of points) and basically a smooth object, deformed.

At some point, that sphere cage breaks and becomes more of a square "bounding box cage"...

I was wondering if we could "force the no change" with a sphere object, or even make a special case sphere object that would keeps the points the same...


If thats not clear, let me know and i'll make a vid to demonstrate...

Hi Burr, well once you have moved a point it is supposed to stay in its deformed state after that. If you see it reverting to the square bounding box type cage (that's the one for the precise sphere with those "fully multiple knots" in it), that sounds like a bug. Do you have any steps you can show to repeat that?

One thing to note is that you'll only get the "smoothly deformable" type sphere points if the sphere is an untrimmed surface. If it has trim curves on it you'll get the bounding box like points.

- Michael

Hi michael,
No, it doesnt revert like the bug you described.

Its the point where it changes from the original sphere points that are presented to the square box points.

I thought i rememberd that it happens automatically after some points are moved to some location relatively, but it definitely happens with an edit frame move.

Give me a bit today and i'll make a vid to see if i can illustrate what part i'm talking about.