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View Full Version : To FREEZE or not to FREEZE, that is the question.



Tom Wood
09-06-2003, 11:45 AM
Hi All,

I'm building some relatively simple characters for a 3D animated show that is all upper torso and talking heads. I want a very simple style made up of 'doughy' components - lots of subpatched boxes and spheres. But I need to add the small 'telling' details like the fold of the lapels and collar of a suit for example, on the surface of a body that -could- be a single subpatched rectangular box (Did I mention simple? All procedural textures too.) I've experimented with using a bezier curve to create a 'drill' that works well enough, but I have to 'drill' the frozen mesh rather than the single polygon of the control mesh because it violates the subpatch when it adds all those points.

So, the question is, what are the downsides to freezing all the actual meshes when it comes time to animate them later?

Thanks,

TW

PS: Regarding that bezier curve drill, what I -really- want is a way to make it act like a smooth shift as it drills from the inside out - moving in three dimensions at once. The line of the suit lapels/collar, for example, are two concentric lines that go up the front, over the shoulders, and around the neck. Exactly matching the curvature of a simple subpatched form but out from the face a small distance. Is there a trick to doing THAT?

txbob
09-06-2003, 01:56 PM
From an animating standpoint, I believe you are better off keeping it a subpatch model.

As far as the detail question... will bandsaw cut your model in the right way?

hrgiger
09-06-2003, 08:02 PM
Well, if you're animating, I would try to keep it subpatch if possible. This way you can also control the level of subdivision if you wish to change it at will. The downside to freezing is that unless you want to get non-planar polygons during animating, you would have to triple the polygons (since by definition, tripled polygons cannot be non-planar) although you could limit the tripling of polygons to areas like joints and other surfaces that will be deformed.

toby
09-07-2003, 05:43 PM
There are ways to get those details that you need in sub-patch mode, like the collar - you just add slices close together where you want things tighter, there are also ways to put in holes and stuff. If we know exactly what you need we can tell you how to do it -

Extent
09-07-2003, 06:07 PM
subpatched modles are also better for animating because you can set the display subpatch level to 0 or 1 instead of dealing with a low poly standin, unless your cage is massively complex as well.

I have yet to find a shape that I couldn't do in quads or tris with a little creativity.

Tom Wood
09-08-2003, 02:00 PM
Thanks everybody -

Toby - That's close to what I'm trying to do, except I subpatched a single large rectangular box (just six polygons, one on each side, to create the subpatched mesh within (the one that shows up in 'wireframe shade' view mode) It's -that- mesh that I need to cut and detail, if I'm doing this right. But the only way to get to it is to freeze it. Am I coming at this all wrong?

Thanks,

TW

toby
09-08-2003, 09:38 PM
No need to freeze at all - a ton of tools are designed to be used on sub-patches.

Sounds like you need to learn the basics - have you read up on sub-patches in the manual?

Tom Wood
09-09-2003, 09:36 AM
Thank you for the help. I -think- I understand the subpatch operation, but I'll admit I'm learning as I go. I have a very specific modeling and animation task in front of me, so I'm concentrating on only the tools I need for that.

Attached (I hope) is an image of the lapels of a suit that I created using a pair of Bezier curves that were fitted inside the frozen mesh of a simple figure. I connected the dots and created polygons. Then I smooth shifted the surface outward, so it intersects and extends beyond the face of the character's mesh, to create a raised surface in this shape that outlines the lapels. But when I smooth shift, I get a lot of weird shading around the polygon edges. Subpatching first helps, but there is still some shading, especially around that group of triangular polygons on the left lapel. I'm going to try it again with a better match in the number of points in the curves so I use mostly 4-point polygons since the 3-point ones are the most trouble to smooth.

But, is there a better way to get to where I want to go?

Thanks again,

TW

PS: I know this is dumb modeling, but it's part of 'the look'.

toby
09-09-2003, 10:13 PM
hmmm.... not so tidy - all those curly lines where polygons supposedly meet -

For one thing, 3 sided polygons don't go well with 4 sided polys, try to do everything in quads - also, you only need to model half of it, then mirror it. It's always safer to have both sides identical anyway.

Learn to use the Knife tool, Bandsaw, and Spin Quads, they're irreplaceable for sub-patch modeling

Tom Wood
09-10-2003, 08:05 AM
Okay, thanks.

The Bezier curves are really cool, but they don't automatically work in symmetry mode, so cut/mirror is the way to go.

I still can't figure out how to name polygon surfaces in subpatch. The white shirt and the grey coat surfaces in the image above are part of the same frozen mesh, with different surface names. But if they were part of the original subpatch, there would be only the six polygons of the original control cage.

TW

toby
09-10-2003, 08:32 PM
naming sub-patch polys is exactly the same as regular polys, select them and hit "q". Only 1 color per poly, no matter how big it is or how sub-divided. Things are sure to change when you freeze them, but there's no need to do that here.

A good option to Smooth shifting is to use it with no offset (click but don't drag), then use the move tool to move the new geometry manually. This keeps things going straight instead of ballooning out if the original polys aren't perfectly flat.

Extent
09-12-2003, 06:58 PM
You need to get rid of all the little eyelet looking like things. Merge points, weld by hand where you need, then delete all 1 and 2 point polys. The way to avoid that is like Toby said, just right click the SS and move the polys.

I'ld also say your subpatch cage is faaarr too dense, you'll get smoother objects that are easier to work with if you cut down the number of polys you use to make them. You could do the collar with at least 8x less polys than you did use.

riki
09-12-2003, 09:41 PM
Generally speaking a frozen object with a high Poly count will render much faster, than a Low Poly SubPatch version. This is because Lightwave has to freeze the Sub Patch Object for each and every frame when rendering the animation.

It should be noted that this is only really suitable for static objects that you don't intend to animate or deform. You should always keep a backup of the original unfrozen SubPatch object as you may need to make subsequent edits to the mesh.

Tom Wood
09-14-2003, 12:58 PM
Hi All,

Thanks to everyone for your help.

Attached is an image that captures my dilemma. The torso is a simple subpatched object made initially of a box that was subdivided three ways on X and Y. The lapels were made using a pair of Bezier curves that were connected by polygons, smooth shifted out, and then subpatched and pasted into the layer with the torso. Sort of a custom drill, just like I wanted. (It missed going over the shoulder, I know.)

I want the coat and shirt to be different colors, but the level of subdivision in the torso is creating that triangle of blue where I want red. If I freeze the torso, I get smaller size polygons and I can hide the line between the colors under the lapel. But it doesn't sound like a good idea to freeze it since this will be animated. I don't want to UV map it either.

Any suggestions?

Thanks again,

Tom

BTW, the cage shown in the first image with the grey suit was the frozen mesh, I didn't make all those polys on purpose.

toby
09-14-2003, 01:48 PM
that will have to be an image map, or break it into 2 different peices.

riki
09-14-2003, 05:24 PM
I should say, it's probably best to get the overall shape of the body right before adding detail like clothes etc.

Extent
09-14-2003, 06:11 PM
Agreed. Your body is going to need a higher density cage than what you've got now. I would seperate the shirt and the coat into seperate objects rather than just use an imagemap for them. I would also model the collar into the coat, getting poly flow is tricky but you'll end up with the smoothest mesh if you do it right, and your deformations are going to look better.

I did a 10 second mock up of what I would start at by reducing the density of the colar mesh you've got already. It's not the way that I would model it if I did it from scratch, but I think that it's the closest way using yours as a base.