Any WIP?
All  1-7  8-11

Previous
Next
 From:  Michael Gibson
57.8 In reply to 57.7 
> The door is solid with pockets rather than cutouts between the webbing.

I see... It was a little hard to tell from the drawing.


> I guess the poly mindset had me looking to create a 45 degree pie piece, followed by iterations.

I think that one of the strategy parts that you're not used to is relying more on doing patterns with curves first, before constructing surfaces.

If you have recognizable 2D curve elements in the design, it is usually worthwhile to focus on creating those curves mostly first and build from there. This is one of the major strengths of NURBS modeling - if you have something resembling a blueprint you have a lot of power to create the blueprint exactly by drawing and trimming curves with each other.


So for doing pockets instead of holes, take the same curves and instead of extruding them all together at once, do all the inside ones first (to select all the inside ones, do a window select to grab everything and then click once on the outside one to deselect it, leaving just the inside ones selected).

This will generate a bunch of separate solid sections. Take these and go to the front view and drag them up away from the base plane. then select the outer section by itself, extrude it up so that it is halfway penetrating through those other pieces. You may now want to select the bottom curves (do this by going to the front view, and doing a window selection from the left to the right that just captures the bottom of the shape - going from left to right captures only what is strictly inside the selection window, going from right to left will show a dashed window border and will capture anything that intersects the window in any way, not only those things that are strictly contained). Hide these curves because they will get in the way a little bit. Then select the base piece, do Boolean / Difference, then select the smaller pieces. This will cut all those pieces as indents into the big piece. Now you can go in there and fillet the edges. Let me know if this doesn't make sense.


> However if I double that geometry and revolve it 180 or 360 degrees around the
> center, one face isnt created.

Yes, I understand what you mean now. Creating it from the center in that manner creates a type of surface that is squished to a single point inside its middle and sort of folded over on itself. MoI is not going to like this kind of a surface, it will generally cause problems. This is not an uncommon problem with revolve, I need to build some helper stuff into Revolve to automatically trim and throw away half of the shape in this case to help you out. But in the meantime when you do a revolve, you should have the shape you're revolving strictly to one side of the revolve axis, not in the center of a shape like you had.

It's a little hard to describe why the revolve from the center of a shape is bad, but imagine if you only revolved it by 30 degrees or so, you would have a single surface that looked like two pieces touching at a point in the center - having the surface squished in the middle of it like this is not good.


> I confess to being a bit vague re the start n stop points, so it's probably user error again.

It can be important to be precise when you're constructing things, because you'll often want pieces to join up with one another. So be careful with just eyeballing things, it can cause problems later on if you're doing a more detailed construction.


> Although I feel a little guilty to be consuming your time.

Don't worry too much about that, I need an excuse to model things and time spent on the forum is actually very efficient for me because it hopefully helps other people at the same time.

- 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:  Spinner
57.9 In reply to 57.8 
Michael,

> I confess to being a bit vague re the start n stop points, so it's probably user error again.

It can be important to be precise when you're constructing things, because you'll often want pieces to join up with one another. So be careful with just eyeballing things, it can cause problems later on if you're doing a more detailed construction.
------------------

In the interest of getting the info out here and my own understanding,
I meant a bit vague in comprehension, rather than execution. As an ex-draftsman, accuracy is ingrained. lol
Intuitively I expect to tell it what to revolve (selection) how far to revolve (degrees in text input) and what axis to revolve on. I'm not clear on how the start and stop points are used to define that axis, especially for the cases it seems designed for, where that axis isnt perpendicular or parallel to the active view window. I'd guess its related to the way an angle is defined but haven't explored enough for the penny to drop. I've successfuly used them to revolve by drawing two points on an axis but what I've inputted by the random distance I chose between them is anybody's guess.

I'm painfully aware of breaking the injunction to keep one's mouth shut and risk appearing stupid, rather than openning it and thus remove all doubt. However, its a good cause and at the least all the experienced nurbists get a good chuckle.

Cheers
Spinner
  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
57.10 In reply to 57.9 
> As an ex-draftsman,

Ah, somehow I had jumped to an assumption that you were coming from a non-NURBS background because of using different modeling techniques such as the stuff called "subdivision surfaces". I shouldn't jump to assumptions about people's backgrounds so quickly.

It's actually quite valuable for me to find out about different things that you find confusing. Hearing about that stuff is how I learn what areas tend to confuse people and can help give ideas on how to improve things in the future.

So when you pick a revolve axis, the distance between the points you pick is not used for anything, the important parts are the location of the base point, and then the _direction_ that is formed between it and the second point. It would probably be better shown graphically as an infinite construction line instead of a line segment.

Think of the axis that you draw as a line that is the pivot pin of a door hinge, where the revolved shape will be created along the way the hinge swings. It doesn't matter if you have a one inch tall hinge, or a five inch tall hinge, they both make a swing in the same direction if they have the same pivot pin. Does that make sense? Let me know if that still doesn't make sense.

The distance you pick can be important to some operations, but not for revolve.

- 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
 From:  Spinner
57.11 In reply to 57.10 
Thats exactly how I used it, so a success for intuitive interface!

re ex-draftsman,
Nope, you were correct on the total lack of nurbs experience.
I hail from the dark ages, when draftsmen drew on paper with pen and ink, engineers used punch cards on big clunky mainframes and all the apples in the office were in lunch boxes. LOL
To a large degree, I'm a good test for Clueless meets MoI. So I'll keep posting and hope its of use.
Cheers
Spinner
  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

 

 
 
Show messages: All  1-7  8-11