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fgreen
10-09-2007, 02:10 PM
Hello, what is the easiest way to sub-divide the poly on the top of a cylinder into a mesh? (see photo).

I know I could use the knife and then weld-average, but it seems like there must be an easier way.

Sekhar
10-09-2007, 04:26 PM
One way is to stencil the top using a sub-divided rectagle that's been converted to a 2-point poly mesh.

If that isn't specific enough:
(1) Create/subdivide to need a rectangle in background layer
(2) Convert it to 2-point poly mesh
(3) Stencil top in foreground with the rectangle in background (Shift+R)

Sekhar
10-09-2007, 05:06 PM
Just realized, just an unweld (Ctrl+U) will do for step 2.

Sensei
10-09-2007, 05:30 PM
Please take a look at EasySplit http://easysplit.trueart.pl
It's general purpose cutting tool replacing almost all LW built-in cutting tools in one and making everything easier.

evenflcw
10-09-2007, 05:59 PM
Isn't this what the Julienne function is for?

Matt
10-09-2007, 06:11 PM
Unless there's a plugin, by hand!

THREEL
10-09-2007, 08:58 PM
Hello, what is the easiest way to sub-divide the poly on the top of a cylinder into a mesh? (see photo).

I know I could use the knife and then weld-average, but it seems like there must be an easier way.

Hey there Fred!

Does the cylinder end need to have a meash of mostly square polys? If not, here's the way I do it.

I hi-light the end polygon and Bevel with 0 Shift and an Inset of what looks good, usually a small amount the first time. I continue to do this, until I get close to the center. Then, I delete the polygon that should be really small in the center. Finally, I hi-light the points that make up the very center and do a Weld Average on those.

Check it out!

tHREEL

BTW--I'm a Buckeye, too.

fgreen
10-10-2007, 06:45 AM
Thanks for all the replies!

Sekar, this looks like a slick method. Should be easy and fast to create and line up a background mesh rectangle with the points on the circular poly for the stencil.

Sensei, thanks for the link. I'll check out the plugin today. For years I've used the knife tool almost exclusively, as either I don't seem to find a use for the others (i.e. quickcut) or they seem cumbersome.

Evenflcw, thanks for the tip, I'll try the Julienne. This is another one I've never used, so I'll dig out the docs.

THREEL, this also looks like a slick and fast method. In this case I think I need squares, as the top will be displaced to represent the surface of fluid in a tank, so different sized polys may not looks as good. P.S. Go Tribe! (unless you are a Cincinnatti fan)

Matt, this would be quicker just to do it by hand, but for once, I'm not in a super time crunch, so I thought, "Hey I bet someone on the forum, has an easier way...".

Thanks again to all. The Lightwave crowd has got to be the most generous and helpful forum around. I'll post again after trying all these methods.

Matt
10-10-2007, 07:46 AM
Hey there Fred!

Does the cylinder end need to have a meash of mostly square polys? If not, here's the way I do it.

I hi-light the end polygon and Bevel with 0 Shift and an Inset of what looks good, usually a small amount the first time. I continue to do this, until I get close to the center. Then, I delete the polygon that should be really small in the center. Finally, I hi-light the points that make up the very center and do a Weld Average on those.

Check it out!

tHREEL

BTW--I'm a Buckeye, too.

I would have suggested this, but I thought he wanted the other way for a reason!

Matt
10-10-2007, 07:52 AM
Finally, I hi-light the points that make up the very center and do a Weld Average on those.

You could merge some of those triangles on the top to make quads too.

art
10-10-2007, 08:06 AM
If you decide to do it manually, you can try to use my lineXline plugin to find all the point intersections and them create polygons using them.

art
10-10-2007, 11:46 AM
You can get yet another kind of topology if you use curves+patch tool.

THREEL
10-10-2007, 12:36 PM
You can get yet another kind of topology if you use curves+patch tool.

Hi Art,

Is this something new in v 9.*? I couldn't find it in 8.5.

art
10-10-2007, 12:51 PM
No, old tools only. A bit of manual work is involved and it works best if the number of vertices on the disc is divisible by 4.
I created 4 curves out of the vertices forming the top of the cylinder.
With those 4 curves selected I applied the patch tool. I checked the "knots" option and set both divitions to 6 (24 vertices forming the top disc divided by 4 =6) I deleted the curves and merged all points.
If the # of vertices is not divisible by 4 , you can still patch it but the resulting geometry will not match the original points and some manual moving/welding is needed.

P.S.: Make curve tool should be on the create tab, patch tool should be on the construct tab. I don't remember 8.x menu exactly but the tools should be there.

fgreen
10-10-2007, 01:56 PM
Tried the Julienne tool, but couldn't get the cuts to line up with existing points on the disc (see screen shots)..

Also tried the Stencil with a sub diivided mesh, but agaih could not get the points to line up without modifying the mesh, so probably no faster than manual method with Knife.

I finally just did it manually using split, knife and weld average. Pretty cool to try these new things though. I threw in a shot of the model. It is for Shockwave 3D process demo. Still have a number of items to create.

Art I downloaded your lineXline plugin, but could not figure out how to get it to work. I tried selecting various edges, but no luck. I looked through your other plugins, also. The Allign Objects plugin is really cool.

Sensei, I took a look at your info on easysplit. Does the line tool snap to existing points (like LwCad's line tool)? If it does, that alone would be well worth the $50-- no more having to weld points like with the knife tool.

Sekhar
10-10-2007, 03:28 PM
Sorry, didn't realize you had to line up the points on circle with the lines. In that case, to continue to sell my stencil method: :)

(1) Center circle
(2) Copy to another layer and set Z of points to 0 (with "i")
(3) Extend the polys ("Shift-E") along Z to make a long mesh and unweld (Ctrl-U)
(4) Stencil circle with this mesh; rotate 90 degrees and stencil again

art
10-10-2007, 03:37 PM
I did this manually in approximately 3-4 minutes (5-6 minutes for slow clickers) with the my line intersection tool. I did 1/4 of the disc and mirrored it twice.

Sensei
10-10-2007, 07:12 PM
Sensei, I took a look at your info on easysplit. Does the line tool snap to existing points (like LwCad's line tool)? If it does, that alone would be well worth the $50-- no more having to weld points like with the knife tool.

Sure, you can see it on this picture:
http://www.trueart.pl/Products/Plug-Ins/EasySplit/Graphics/EasySplit_Split.gif

At first cut, Merge Tolerance is little too far existing points, and in second frame I am adjusting it in Numeric window, so it "finds" real existing points..