Hi there,

I don't know how to get this shape in Moi
Please help me


Thanks,

M

Hi moontooth,

One method that can be good for a rounded cap is to actually model the cap itself as an independent surface, and then boolean and fillet that with your base piece.

In order to do that, you would kind of extend the base piece to be taller and continue kind of straight for a while rather than trying to manually model what the filleted pieces will be later.

To give you an idea, something like the following.

I first tried to stretch your shape upwards and taper it in just a bit (not too much, you still want the fillet to do most of the rounding work, but you can kind of continue to shrink the shape downwards).

Then I drew 2 curves at 90 degree angles to one another:



I used Construct / Sweep to sweep one curve as a profile along the other one as the rail path, to make a rounded cap surface like this:



Now solidify the base piece by selecting it and running Construct / Planar to cap off its planar open ends. Then select the base piece, so that looks like this:



Now do a boolean difference, and use the rounded cap as the cutting object. That will slice the base piece into 2 pieces, select the top piece:



And then delete it, now you can select the top edges or the top face, and do a fillet to smooth out the juncture between the rounded cap and the main body:




This one was done quickly and roughly to just give you the idea, but you can mess quite a bit with the shape of the sweep curves to control the shape of the cap piece, and it also helps if you have kind of planned in advance for the main shape to extend itself upwards a bit more naturally rather than having it stop so suddenly.

Hope this helps!

- Michael

Thanks for your fast reply Michael,

yes, this way can get some thing like that shape, but without great precision.

my client wans a super precision model with super smooth surface.

:(

Hi moontooth - you can get more precision by controlling the shape of the curves you use for the sweep.

Adjust those curves until you have the rounded tip shaped how you want.

It tends to be easier to adjust a more localized part of the overall shape like this rather than trying to build the whole thing all in one single surface pass. Trying to do it all in one single pass gets hard to control when the shape is changing.

You have a pretty major shift in shape in this case, because you've got a profile that is like 3 lines with arcs between them, but the rounded tip part that you show in your example does not have that kind of a shape, when there is a shift in shape like that, that is often a clue that it is good to develop those shapes as separate surfaces and then fillet them together to produce the final result.

You may want to use the Shape = G2 fillet option when performing the fillet, that will make it so that the fillet piece shares surface curvature with the surrounding pieces, it makes the fillet blend in more seamlessly with the other pieces.

 

Otherwise if you want to get even more fine tuned control, your main other choice is to use a sub-d type modeling program instead of MoI, but then you will be basically manipulating every single point of the surface cage to a good spot which can be a bunch of work.

- Michael

See post here:

http://moi3d.com/forum/index.php?webtag=MOI&msg=2908.9

Hi moontooth and Michael G.

Here is something I came up with using Network of curves and blending.I don't know if it will help, but here it is.