FXWARS THE RACE: TIPS & TRICKS!


#1

Post here your ideas and tricks used for this challenge.

Know how to do a matte painting? Post it here.
Know how to do a pull a matte from video? Post it here.
Know how to fog/storm effects your favorite compositor/3d program? Post it!
Know how to do complex camera matching/ lighting set up? Post it!
How do you do realistic car rig?
How do you do model a race car?

Looking forward to the posts, but please try to keep it
as application agnostic as possible.


#2

simple constraints set up for tires to the ground
(to remove, if you want to animate the tire flying away, key the constrains off, it’s the setting in the constrain NOT called offset something)

hierarchy
car_group (this is how you animate the position and rotation of the car)
|–carBody_group (this is where you animate the body to give it weight and bounce)
|–tireRF_group
|–tireRR_group
|–tireLR_group
|–tireLF_group

create cubes
make non-renderable and override the shading display so they are just wire… or hide when you are done with the set up.
flatten duplicate and place under each tire
geometry constrain these cubes to the ground
…if you don’t have ground yet leave it until you do or make a test one and delete and remake the constraints when you do.
create a parent constrain, for the cubes under the tires to the car_group
point constrain each tire to their respective cube (those cubes above you just made under each tire)
offset the point constraint so that the tires sit on the ground and are not going through it.
limit the Y trans if each tire_group to the min and mad dis the tire should be from the body of the car.

play with the car and see how it tries to keep it’s tires on the ground. This isn’t the best but for our needs it should be good enough. It would be even better if it had dampening attributes but again we want quick and dirty get this part done, right? we want to get on to FX!

***I didn’t do shocks but if I would, I would parent them to the tires and set driven key them to scale/slide with the Y trans of that tire… Don’t get caught up in that kind of crap, it won’t pay off in the final shot, (well maybe formula one)

I added an atttr to the car_group called tireSpinSpeed and made an expression on all the tires that says

tire.rotateX = time*car_group.tireSpinSpeed;

then you can just key the one attr. again not the best but easier than trying to get the spin to work on the ground

if I come up with something better after more testing I’ll post that. I may still post my mb files. I’ll write to turboSquid and well see. Hey, the rules haven’t even come out yet, I’ve only been messing around so far :slight_smile:

One more tip I’m going to draw a curve on the ground surface and then raise it up a bit and use it as the animation curve, tweak it a bit. then I’ll just animate the rotation and the car body. The point isn’t for most realistice car animation, its all about the crash, I think this will give me a good look in a short amount if time, again so I can get right to the fx.


#3

Awesome contribution destruct007!!!
I can’t wait to try that out tonight at home!

Thanks a lot!

Xavier.


#4

As for actually doing the crash, if you want to crumple it up, you can use cloth simulation to get a base for the simulation. Then, if you are able to (this is possible in Maya), you can bake it out to a blendShape, and tweak the shape and timing of it to what you want. Possibly you can get tension maps out of the cloth simulation, and use that to drive additional high-detail displacement/bump maps, or other shader parts.

A combination of rigid and soft bodies can be used for a lot of the other stuff, like bumpers and wheels. Rigids to move the object overall, and softbodies to deform/dent it a bit.

Just some thoughts.


#5

Hey destruct007, i don’t understand what is different between parenting the constrained cubes to the car’s tires, than from just moving the Car_Group in only the x and z axis…which could be done by locking the Y axis.

I might be missing something here.


#6

It took me a while to get what you are saying I should have been more clear I wrote

“parent constrain these cubes to the car_group”

I mean… create a parent constrain, for the cubes under the tires to the car_group

I’ll edit that above to be more clear


#7

http://www.lamrug.org/resources/doc/paint.html

all you need to know, I’m not persay going to use this for my project of rally cars but to sweening some rides check it out.


#8

ok well another post from me, ah this is three in a row, whatever, aaaanyway,

people were suggesting I add camera shake to my camera, well it’s kind of annoying to just animate that my hand, inaddition to already getting the right camera animation, so I scripted it together and here’s the Maya 7.0, WinXP file,

 right click save as
 [http://agentfx.com/fxWars/camShakeLoc.ma](http://agentfx.com/fxWars/camShakeLoc.ma)
 
 should that not work for you here's how to do it by hand,
 
 make a locator
 name it loc1
 group it name the group camShakeNode
 add attrs
 camShakeSpeed min 0 default 1
 camShakeSize min 0 default 1
 (this code adds the attrs)

     addAttr -ln camShakeSpeed -at double  -min 0 -dv 1 |camShakeNode|loc1;
     setAttr -e -keyable true |camShakeNode|loc1.camShakeSpeed;
     addAttr -ln camShakeSize -at double  -min 0 -dv 1 |camShakeNode|loc1;
     setAttr -e -keyable true |camShakeNode|loc1.camShakeSize;
     
 then this is the expression to put in the translate.(anyone of them)

     float $sinX = (sin(time*loc1.camShakeSpeed))*loc1.camShakeSize;
     float $sinY = (cos((time*.5)*loc1.camShakeSpeed))*loc1.camShakeSize;
     float $sinZ = (sin((time*.8)*loc1.camShakeSpeed))*loc1.camShakeSize;
     
     loc1.translateX = (sin(time+$sinZ)*$sinX);
     loc1.translateY = (sin(time+$sinY)*$sinY);
     loc1.translateZ = (sin(time+$sinX)*$sinZ);
     
 Ok now to use it group the camera you animated to nothing, then parent that group under the loc1. 
 the Size is how far the locator moves and the speed is how fast it moves.
 Enjoy hope that helps.

edit: I can’t get the spaces out of the code
camShakeS ize
that should be
camShakeSize


#9

As an alternative to David’s camera shaker script (which may be a bit of a rendertime hit, if you have motion blur turned on), you could always do the camera shake in compositing. This is pretty easy in either Shake or After Effects, by scripting a noise function to tweak the plate’s X and Y position. Just make sure to over-render your shot a bit, so you can scale it down and then move it in comp.


#10

An alternate to cloth and softbody crumpling/deformation, and depending on level of detail, one could easily animate a lattice on the object to be deformed. Much faster too.


#11

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