|12 December 2002|
Vision Lab / ImageSociety
Rio de Janeiro, Brazil
Problems to make a Wire behavior.
I'm trying to make a similar Lux-Luxo (Pixar ) animation.
So... there's wire that connect the lamp to the wall-socket (electric power)...
The problem : I'm using 3ds5 and I decided to use the Reactor facilities. So... I created a SpLine, and attached the rope modifier to the vertexs located between the first vertex and the last vertex.... I have set the first vertex to be an unyield one... And attached the spline to the lamp base.... That's nice and working... when I move the lamp (like jump movements) The wire works Ok... BUT I'm having problems to make the last vertex setup.... This vertex should be connect in the socket... So.. Don't move... how can I do that ?
How can I use the reactor rope, with a Spline that the last vertex is Fixed and the first vertex connect to a object (that jump). ?
thank you a lot...
sorry for the english...
|01 January 2003|
Creating a realistic animated cable/rope/flex in 3D Studio MAX
The effect of creating a realistic animated cable has long been sort after for users of MAX and most 3D programs.
I came up with the following solution after a conversation with Jarno Cordia (http://www.3dluvr.com/mccordia) He showed me a work in progress animation he had done which had a perfectly animated wire/rope effect. I asked him how it was done, and he said he used the free Sim cloth plugin (http://www.chaosgroup.com/) and a lot of experimentation. My attempts at trying this before had not been too convincing, but knowing it was possible gave me a challange. By the next day I'd recreated the effect, and on comparing notes we had done it exactly the same way.
The problems I'd encountered when first trying the effect with Simcloth was how to maintain a cylindrical "rope" without it collapsing in on itself and becomming 'ribbon' like. Hours of playing with the bond range and bias gave better results, but there was always crimping and folding which ruined the illusion.
I was reading through the Sim Cloth help files and something clicked when reading about the bond range. If every vertex is pulling on the other equally then it stands to reason that a triangular prism cannot collapse inwards......
Making a Cable follow a Mouse.
Here's the idea in practice to make a mouse lead follow the movements of a mouse. My anim can be seen here.
Download Sim Cloth from http://www.chaosgroup.com. It's an amazing plugin and what's more its completly free. If you haven't already tried it then I recommend doing the tutorials on the site and familiarising yourself with it.
Create a plane in the top view, this will be our desktop. Assign the Sim Cloth modifier as a deflector.
Create the object to which the cable is connected. In my example I used a detailed computer mouse, although for speed and the sake of this tutorial you can use a simple cube.Apply the Sim Cloth modifier to it, and set the Type to deflector. This will stop the wire moving through the mouse later. Make sure that the Mouse doesn't intercept the desktop at all.
Create a Ngon (Create/shapes) in one of the side viewports. Give it 3 sides to create an equilateral triangle.
Extrude the triangle to the length required for the wire. Increase the segments so that they form fairly square faces. This will ensure that the wire can bends tightly (if required.
Move and rotate the extruded shape into the position required. (ie. ajoining the mouse) NB: Do not place the end of the wire intercepting the mouse as this we be dectected in the simulation and seen as an error.
Select and link the wire to the mouse.
Apply mesh select to the wire and select the vertices closest to the control object. These vertices will remain rigid in the final simulation, so you may want to select the last inch or so of the wire nearest the mouse. Soft selections can also be used.
Apply the Sim Cloth modifier to the wire. Change the Type to cloth.
Under Dynamics change the bond range to 1.5. Because we are using a triangular structure I think this only applies to the way the vertices react with each other along the length of the wire. (don't count me on that..) A value of 1.5 just gives the wire a little rigidity.
Go into subobject mode and select the vertices at the other end of the wire - the end that we want to remain motionless (as if plugged into a computer) and make a New vertex group. Click on this (group_01) and then scroll down to the Attached box and tick it. Click the empty space and then select the desktop plane. Tick Attach to surface and Attach by Pos.This locks the end vertices where they are as they are noe connected to the desk, and the desk aint going anywhere. (of course it's up to you what you connect it to, it could be another moving object).
Now we need to enter some animation for our mouse object. I used the Motion Capture feature in the utilities panel to capture my own mouse movements, but any other form of animation is valid. Nothing to fast or jerky for now, but make it last for about 100 frames to get an idea of the flow of the wire.
Select the wire and in the Sim Cloth roll out hit "Start Calculation". If all has gone well you can watch the computer solve the wire dynamics as the mouse moves. As the shape is 3 sided the solution should be quite fast. You may get some errors at this stage, these are explained in the Sim Cloth documentation and may need some tweaking of settings.
After the solution is finished hit play and watch your simulation. (on slower computers you may want to render a preview) It's unlikely that you'll get the right results first time - more often than not the wire will move too fluidly. Increasing the Slip, Gravity, and Air resistance will illeviate this. Again reading the Sim cloth documentation will give a better idea of what these effects actually do. Remember to Clear the sim before trying new settings or wierd things can happen.
When your sim looks good add a Nurms mesh smooth modifier on top of the Sim Cloth. Our triangular wire becomes a hexagonal wire. You can step up the iterations, but it looks fine like this for the most part. IMPORTANT: Do not go back and tweak Sim CLoth settings with Meshsmooth on top of the stack - Sim Cloth should always be at the top or all manner of horrible things can happen.
So there you go, tweak away and play. Remember you can use the vertex sub object mode in Sim Cloth fine control areas of the wire (eg to Weight the ends), and you can use Rigid body objects to interact.
I only discovered the whole prism based wire idea a few days ago and haven't had time to extensively test it, but it seems to work pretty well. Here are some of the tests I did whilst working on the idea:
|01 January 2006|
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