Surface to Solid

Next
 From:  scott (SSHWARTS)
6574.1 
I'm back with another question (peddling as fast I can to come up to speed). I have the attached model where I have two problems with it. One is that because (I presume) of the way I constructed it, it's all Surface (less two small pieces which are cylinders). I'm having a difficult time closing it up. I can see the edges with the script but am confounded as to what to do next.

As part of that, I need to close up the hole at the bottom of the part so I can attach a cylinder of the proper diameter (the one I had was the wrong size and I used a boolean operation I should not have an cut a hole).

To create the part to begin with I drew a profile with polyline and then extruded it. Was there a better way I should created it to begin with to avoid this mess?

Can someone point me in the right direction?

Thanks
Attachments:

  Reply Reply More Options
Post Options
Reply as PM Reply as PM
Print Print
Mark as unread Mark as unread
Relationship Relationship
IP Logged

Previous
Next
 From:  Michael Gibson
6574.2 In reply to 6574.1 
Hi scott, that's kind of a mess... There's a lot of pieces there that are not lined up with each other like at a bit different z levels, and slightly different widths and stuff like that, once you start booleaning together stuff that's all just a bit off like that you end up with a lot of little slivery fragments since there tends to be a lot of left over little pieces...


> To create the part to begin with I drew a profile with polyline and then extruded it. Was
> there a better way I should created it to begin with to avoid this mess?

You'd probably want to use Draw curve > Freeform > Control points to draw those areas instead of polylines.

Basically if the result is supposed to look like a smooth curve you will want to draw a smooth curve to represent it, that will make a lot more optimized final result since you'll get large smooth surfaces generated from the smooth curves.

If you try to make something that is supposed to be smooth but only draw it using polylines, you're not going to end up with an actual smooth result since a polyline is made up of a lot of little straight line segments and you'll end up with one surface generated for each of those little lines. That will cause a lot of additional complexity in the final result because you'll have a lot more faces and edges in your final model.

Polylines should be mainly used for things that have pronounced sharp corners in them, if you have something that has some sharp corners and some smooth then you can use both tools in sequence - you can use a polyline for the sharp spots but when you come to a smooth area, exit the polyline command and start up the Draw curve > Freeform > Control points command to draw a smooth curve and make sure "Object snap" is enabled in the bottom toolbar so you can snap the first point of the smooth curve onto the end point of the polyline you just drew. You can also use the freeform curve drawing tool to do the whole job by holding down the Ctrl key when you click to make sharp corner spots.

Do you have any earlier versions of this object saved off with the curves you used? It would probably be a good idea to edit some of those curves first and then reconstruct the object, a few things to edit would be to make smooth curves in those spots where you currently have a lot of line segments, and also to edit some of the side pieces so they aren't at a slight angle, right now for example the bottom edge of the side piece here isn't flush with the other part:



It looks like it's rotated at some slight angle, one side is higher than the other parts, and the other side is lower:






It's good to take a bit more time and preparation at the curve drawing stage when you get some of the initial curves drawn, zoom in a ways on the curves to make sure things are looking good, and also you usually want to draw things with both "Object snap" and "Straight snap" enabled on the bottom toolbar, those will help you to draw things that are accurate, what you don't want to do is to have those turned off and just kind of move your mouse around so that things sort of just look ok at your current zoom level, that type of eyeballing will leave things inaccurate and then later on when you go to construct surfaces from all the stuff your surface and solid model will inherit those same problems.

- Michael

  Reply Reply More Options
Post Options
Reply as PM Reply as PM
Print Print
Mark as unread Mark as unread
Relationship Relationship
IP Logged

Previous
Next
 From:  Michael Gibson
6574.3 In reply to 6574.1 
Hi scott, also another note:

> To create the part to begin with I drew a profile with polyline and then extruded it. Was
> there a better way I should created it to begin with to avoid this mess?

Also I'm note entirely sure if this spot here you wanted to follow the same exact circular shape as the cylinders:




If you did want that to have the same circular shape as the cylinder that pokes out from it, (just at a larger diameter), then you'd want to use one of the arc drawing tools for drawing that part (Draw curve > arc), and not the freeform curve drawing tool for that particular section.

Also sometimes it can be more convenient to draw in a big circle and then use Edit > Trim to cut it with a line rather than drawing in an arc. In the case here if you wanted to have a certain thickness that goes around the cylinder it might be convenient to generate the circle by selecting the cylinder's edge and then running Construct > Offset to make an offset curve from that and then that will give you the bigger circle to trim with a crossing line.

- Michael
Attachments:

  Reply Reply More Options
Post Options
Reply as PM Reply as PM
Print Print
Mark as unread Mark as unread
Relationship Relationship
IP Logged

Previous
Next
 From:  scott (SSHWARTS)
6574.4 In reply to 6574.3 
I appreciate you taking the time Michael to help me not only learn the program but better my overall skills. Everything I've done in the past is far more parametric (OpenSCAD for example is easy for me but I'm limited by it) so actually drawing to some degree of accuracy is new. I also need to learn better control or I end up moving things around and making a mess. Again thanks for taking the time.

One feature request and perhaps there's a script for this already...but I'd like to be able to save quick snapshot files before I do something potentially destructive to my model. Could just be enumerated foo0001, foo0002 et al. While Undo is of course great, often I can't really see what I undid to backstep to the right place. I save often so sometimes just going to last saved is not enough (I've had some crashes on Mac).

Scott
  Reply Reply More Options
Post Options
Reply as PM Reply as PM
Print Print
Mark as unread Mark as unread
Relationship Relationship
IP Logged

Previous
Next
 From:  Frenchy Pilou (PILOU)
6574.5 In reply to 6574.4 
<< Could just be enumerated foo0001, foo0002

http://moi3d.com/forum/index.php?webtag=MOI&msg=3756.2
  Reply Reply More Options
Post Options
Reply as PM Reply as PM
Print Print
Mark as unread Mark as unread
Relationship Relationship
IP Logged

Previous
Next
 From:  scott (SSHWARTS)
6574.6 In reply to 6574.5 
Wow. It's like whatever you want it's there somewhere.

Tea, Earl Grey, Hot.

Thanks!
  Reply Reply More Options
Post Options
Reply as PM Reply as PM
Print Print
Mark as unread Mark as unread
Relationship Relationship
IP Logged

Previous
 From:  DannyT (DANTAS)
6574.7 In reply to 6574.6 
~Danny~
  Reply Reply More Options
Post Options
Reply as PM Reply as PM
Print Print
Mark as unread Mark as unread
Relationship Relationship
IP Logged
 

Reply to All Reply to All