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View Full Version : Make Poly "p" yields faceted surface?



Johnny
04-27-2004, 03:01 PM
I've run into this a bunch of times, and have been able to "hide" it most of the time, but don't want to do that anymore bcs it seems limiting, and not proper modeling technique...

I'll make a disc, and bevel out the shape I want. One end will have a proper, smooth surface, and the other end will be open in the sense that there is no poly there.

I select the points, hit p to get the poly, and wind up with noticeable facets even after hitting the tab key.

Is my method for beveling out my shape incorrect to begin with, or is there some trick to make the poly I create un-faceted?

If necessary, I can post a screen grab to show what I'm talking about, but I bet everyone's seen what I mean.

Thanks!

Johnny

JulianW
04-27-2004, 04:09 PM
Hi,

I can' quite tell what your doing, so a grab might help. From what you say I wouldn't use make poly, I'd simply start by flipping the poly, hitting 'c' for copy, then undoing the flip. When you want to put the end back on the shape just hit 'v' for paste and 'm' to merge points.

The other thing to remember is that sub patching only works on 3 or 4 sided polys.. so you might need to use the Multiply:Extend:Spikey tool on the discs at each end.


JW.

mkiii
04-27-2004, 05:58 PM
This may sound stupid, but why don't you give the disc some depth when you first create it, by dragging it out in the long axis?

Do you get the same results if you use extrude rather than bevel?

As for the faceted end poly, I think we do need a screengrab - but it does sound a bit like what you would get if the end was a fan of tris & you'd turned on sub-divs

Johnny
04-27-2004, 06:02 PM
http://home.earthlink.net/~zoomin/poly.jpg


Here's what I did: I began with a disc with the intent to make the shape of a cork (simple cylinder with rounded edges).

I beveled from the top downward, making the 'skin' of the cork. I finished at the bottom, whose surface was smooth, as you'd want. I was left with a 'hole' in the top. This is where you see the faceted surface in the jpg I posted. (this is looking basically downward on the cork; the lighter grey is the top surface, the darker is the side of the cork).

I'm wondering if my method of making the cork or a bottle or anything with a round cross section which can be easily beveled out isn't wrong because it leaves a hole at one end or the other - that end depending on whether you flip the original disc or not.

I could see beginning with a cylinder and then modifying it into a cork shape (the one I want isn't 'perfect') but this doesn't solve the same problem I run into making bottle shapes.

Thanks!

J

riki
04-27-2004, 06:47 PM
Hi Johnny, maybe a shaded wireframe screenshot would be better. Also zoom out a touch so we can get some sense of what we're looking at.

bloontz
04-27-2004, 07:13 PM
If your disc was greater than 4 sided, the poly you created would be greater than 4 sided and will not work with sds. Your screenshot looks as if that could be the problem.

mkiii
04-27-2004, 07:49 PM
Agreed. That's what it looks like. Johnny. you need to mention things like 'I'm using a sub-d mesh'' when you ask stuff like this, even though we pretty much guessed that anyway. it helps to clarify matters.

Oh - and your best bet for forming this cork shape and the bottle it goes in is to draw an outline spline curve or polygon shape (using the pen tool is best), in the front view & use Lathe to get the shape. Use a low subdivision if you are still going to use sub-ds on the result.

Johnny
04-27-2004, 08:37 PM
Originally posted by mkiii
Oh - and your best bet for forming this cork shape and the bottle it goes in is to draw an outline spline curve or polygon shape (using the pen tool is best), in the front view & use Lathe to get the shape. Use a low subdivision if you are still going to use sub-ds on the result.


I'll try that.. would you recommend that method also for things like bottles, glasses and bowls? IOW, things that look as though they *could* be lathed in reality?

J

Johnny
04-27-2004, 08:38 PM
mkii;

don't know about the extrude vs. bevel, but it's worth a try after dinner!

here's the screen grab: same item, one wireframe, one textured, same camera angle.

the crude white arrow points at the faceted surface in question.

thanks again!

J
http://home.earthlink.net/~zoomin/cork.jpg

Johnny
04-28-2004, 12:26 PM
Originally posted by mkiii
Oh - and your best bet for forming this cork shape and the bottle it goes in is to draw an outline spline curve or polygon shape (using the pen tool is best), in the front view & use Lathe to get the shape. Use a low subdivision if you are still going to use sub-ds on the result.


When I try this method (pen or spline) I get some results which are puzzling to me...the screen grab shows what I get right after lathing (and making extra-certain that I lathe about the vertical axis precisely) and what happens when I hit the Tab key.

None of my reading the manual has tipped me off to what's up with this strange sort of vortex puckering-looking thing.. or the holes, or in this case, half-holes that I also get.

Any thoughts?

Thank you!


J

http://home.earthlink.net/~zoomin/huh.jpg

bloontz
04-28-2004, 12:44 PM
Sds, what you get when you hit the tab key only work on 3 and 4 point polys. That is why the top poly created by your beveling method is faceted, it's greater than 4 sided and can't be converted to sds.

In your lathe, you shouldn't have a closed spline to lathe an object lke that, you would want a open spline that ends at the axis you are using. By using a closed spline you are creating unwanted geometry in the center of your cork. Hope that makes sense.

Johnny
04-28-2004, 01:19 PM
Originally posted by bloontz
Sds, what you get when you hit the tab key only work on 3 and 4 point polys. That is why the top poly created by your beveling method is faceted, it's greater than 4 sided and can't be converted to sds.

In your lathe, you shouldn't have a closed spline to lathe an object lke that, you would want a open spline that ends at the axis you are using. By using a closed spline you are creating unwanted geometry in the center of your cork. Hope that makes sense.


I *think* that's what I created; an open spline..it sort of resembled a "U" on its side, with the open end pointing right, and the beginning and end of the spline lining up on the axis of lathing. Is that what you mean? (here I'm talking about the pen method of making my profile to be lathed, as opposed to the beveling out of a disk, as before in the original post.)

J

bloontz
04-28-2004, 01:27 PM
Sounds like you are doing it right, make sure that the end points are on the axis, either using snapping or Set Value. You shouldn't be getting that extra geometry.

hunter
04-28-2004, 05:04 PM
Here's an idea...

hunter
04-28-2004, 05:09 PM
Where's my image dammit:)

riki
04-28-2004, 05:27 PM
Here's a method I use for capping a disk

http://www.suture.net/tutorials/modeling/img/109.gif

mkiii
04-28-2004, 05:57 PM
There are about a dozen ways to skin this particular cat. Best to try em all & decide which one you 'get' the most.

hunter
04-28-2004, 06:19 PM
Oh sure Riki, if you like doing it so few steps ;)

Nice and easy. I think I'll use that from now on. Never even think about spikey.

riki
04-28-2004, 06:45 PM
LOL

I like this method also because no tris, keeps the poly count down. Plus I like to work with a system of 8, it matches up well with other primitives.

Johnny
04-29-2004, 12:14 AM
Dang! went out for a movie and drinks and returned to a wealth of great techniques..

thanks very much!! I can see how all of these methods will help me to tackle modeling issues as they arise..

Johnny