PDA

View Full Version : making a rectangle turn a corner



Johnny
04-30-2008, 09:33 AM
I need to make a rectangle turn a corner; picture a piece of cloth in the air, flat, parallel to the ground, moving parallel to the ground, then the leading edge of that cloth makes a 90-degree turn toward the ground, either with a sharp crease, or a rounder radius of turn.

would I do this with bones? or is this a job for expressions? I'm pretty inexperienced with the former, have never tried the latter.

I can imagine my rectangle shape is going to have to have a fair amount of subdivisions in it so that when it bends around its corner, it'll look smooth.

thanks!

J

Nangleator
04-30-2008, 11:31 AM
I'd try it with the morph over bones trick. Just make a chain of bones that form the motion path you want your sheet to go over. Then create a morph that positions the sheet far along the axis of movement. There are a few other steps. Let me know if you need to know them.

More simply, there's a motion modifier. Inertia? Use that plus a Pitch Controller for "Align to Path."

Johnny
05-01-2008, 01:37 PM
I'd try it with the morph over bones trick. Just make a chain of bones that form the motion path you want your sheet to go over. Then create a morph that positions the sheet far along the axis of movement. There are a few other steps. Let me know if you need to know them.

More simply, there's a motion modifier. Inertia? Use that plus a Pitch Controller for "Align to Path."

OK..I'm going to try that...I'm using 8.5d, btw, so I'm assuming I'll encounter all the tools and features I need for this.

thank you for the tip; I should be able to begin with it sometime today!

Johnny

Nangleator
05-01-2008, 02:12 PM
Let's assume you want your sheet of paper to move at least initially in the Z positive direction.

1. Model it so the "front" is towards the Z positive.

2. Make a morph that involves moving the whole thing in that direction.

3. In Layout, draw bones for your paper that will represent its motion path.

4. Select "Use Morphed Position" in the bone settings dialog.

5. Animate the morph over time and watch the fun.

It's far easier to set up the bone chain in Modeler, but that adds quite a few more steps. For instance, the heading and pitch bone rest positions have to be all set to zero.

Oh, and it might make sense once you have the bone chain set up to duplicate the whole heirarchy of bones, so you have 2 or 3 parallel sets. You'd need that if the paper warps strangely over a single chain of bones.

Johnny
05-01-2008, 02:29 PM
Nangleator;

thanks both for the step-by-step as well as the caveats...I believe I've made bones in Layout; not sure how that went, but I will proceed in the direction you suggest.

Johnny



Let's assume you want your sheet of paper to move at least initially in the Z positive direction.

1. Model it so the "front" is towards the Z positive.

2. Make a morph that involves moving the whole thing in that direction.

3. In Layout, draw bones for your paper that will represent its motion path.

4. Select "Use Morphed Position" in the bone settings dialog.

5. Animate the morph over time and watch the fun.

It's far easier to set up the bone chain in Modeler, but that adds quite a few more steps. For instance, the heading and pitch bone rest positions have to be all set to zero.

Oh, and it might make sense once you have the bone chain set up to duplicate the whole heirarchy of bones, so you have 2 or 3 parallel sets. You'd need that if the paper warps strangely over a single chain of bones.

Dirk
05-01-2008, 05:24 PM
You might also wanna try SplineControl. You can set the movement path with the control nodes and move the object through movement of node 0.

Surrealist.
05-02-2008, 05:26 AM
There is also the Serpent plugin which can deform the object along a path.

Johnny
05-02-2008, 09:50 AM
well, I was making some nice progress last night when the sand man showed up with a bazooka! I was pretty pooped and had to call it a night..

I can see, from my nascent efforts, that 3 or more bones chains will be needed to make the sheet bend in unison, as opposed to just the corners bending ahead of the middle.

I greatly appreciate the suggestions of other techniques or plug-ins for doing this thing, and will prbly try them all whether or not the bones method works.

Thank you!

J

3DGFXStudios
05-02-2008, 10:56 AM
why not use the simple bend modifier? or did I miss something

3DGFXStudios
05-02-2008, 11:04 AM
Like this

Surrealist.
05-02-2008, 11:43 AM
I think it is supposed to be moving and flow through the bend. That is if I understood the description correctly.

Johnny
05-02-2008, 02:17 PM
I think it is supposed to be moving and flow through the bend. That is if I understood the description correctly.

yes. that is correct.

this rectangle will be moving horizontally, then the leading edge will turn 90 toward the floor, and the effect, when all's done, will look like a piece of cloth which was slid across the top of a table, or cube, and when it arrives at the edge, gravity pulls it downward.

that's the basic idea..the cloth will not be waving or rippling the way real cloth would; I'm simply going for this 90-degree turn.

thanks!

Johnny

Nangleator
05-02-2008, 02:49 PM
Heh. You could get tricky and build the whole thing as one piece, then animate a clip map so it appears to follow the path.

archijam
05-02-2008, 03:11 PM
Here's a very nice scene (http://www.newtek.com/forums/showpost.php?p=188770&postcount=3) to dissect from Lightwolf ..

Johnny
07-16-2008, 07:38 PM
OK. "uncle"

I give..what's the trick?

I've been examining and tinkering with lightwolf's scene on and off for weeks...I hate to admit it...

I think I know the idea behind what he did but I can't get the implementation.

help?

thanks

J