#Animated Skid Marks
11 messages in this thread
Once again it is time to tap the resources of the experts on this forum.
You know, "a has been under pressure." Just kidding you guys and gals.
How can I animate the skid marks of a car as it is sliding. The skid marks
need to follow each tire as it happens. I would assume this would be done
as a flic and then mapped onto the road surface. Could this be done
entirely in 3D Studio. If its going to be a map, how would you scale and
coordinate etc. the map so that it fits correctly into 3D Studio.
Thanks in advance Rick
Rick:
You can make up a 'flat' object that has more faces than it needs when it
is 'near 0 length'. Then, you simply morph it to the final 'bent' line on
the pavement and animate the sucker… (This 'flat' object is actually a
near flat square tube with alot of steps in it when it is lofted.).
I'm sure someone will have another idea that is alot better than this…
which is why I only do this for fun <g>.
C#
Thanks Craig for your idea on morphing. I still see a problem with making
the objects to fit the slid close enough that it appears under the tires
and not off to the side. I don't have any numbers for the skid marks,
therefore I would have to create them by looking at how each tire moved,
looks like it could take some time to get it right. I hope I don't have to
animate Danny Sullivan's 360 degree slide at the Indy 500 a few years back.
Thanks again….. Rick
I'd use AniPro to create an animation of the skids as an animated texture
map. First, render a flat-shaded animation of the 3D scene from directly
overhead. Bring that flic into AniPro and use it to create an animated
texture map of the road surface with the skid marks, then map that flic
back onto the road object in 3D Studio and render it.
– Jack
Rick:
Yes, I see what you mean. Jack's idea won't help you either if the tires
aren't on a predictable path. The idea I posted would mean that you would
have to morph the skids one frame at a time. I would imagine that someone
could write a C program that could be run as an external application to
make part of an object morph to another. I'm not big on animation but you
could use an overhead view to make a movie of the tires only. Make a flic
of the tires and take it into Animator Pro. Use the tires with scrape ink
to 'reveal' the skids… (maybe that's what Jack said afterall…<g>).
C#
What I was suggesting, Craig, was that he make a draft flic from 3DS of the
car animation. It doesn't matter if the tires aren't on a predictable path,
because he would essentially rotoscope the skid marks directly over the
draft flic, then erase the rest of the flic and create a pavement, etc…
– J
As with most problems there may be several solutions. You could create flat
geometry with the tire pattern (painted in animator) textured onto the
object. This could be scaled along one axis (the direction of the slide) as
the animation proceeds. Make sure the object's pivot point is at the
beginning of the skid. This only works well with straight skid marks. If
the skid marks are erratic you could paint the entire skid in animator in
black on a grey background (for the texture) saving this as a cel or gif,
then make an animated opacity map (in white on black) of the whole skid
mark. To do this you could start on the last frame in animator pro and then
remove a bit of the skid (draw over it in black) then go back one more
frame and remove a bit more, until you have removed it all over the number
of frames you want. Make a meterial in 3ds with the texture map (.gif) and
the opacity map (.fli). Hope I haven't confused you. Morphing could work,
too, as the other reply stated, only it's not good for complicated skids.
Martin:
You are not trying to tell me that there is not, "ONE PERFECT SOLUTION."
How will I ever be able to handle it <grin>. Seriously, thats what I like
about 3D Studio, you have to be a creative problem solver to enjoy this
work.
Most likely my skid marks will not be perfectly straight. Let me number my
questions for easier reference.
1) How would you paint the skid marks such that they were the right
width, length and curvature to fit into 3D Studio and appear under the tire
making the skid? Can you use pixels some how to provide a dimension to work
with?
2) How would you know how much to erase from each frame? The car is
not moving the same distance in each frame, in fact it is different in
every frame. The answer to question #1 may provide the answer to this
question.
3) Why use the opacity map, could you just animate the black skid mark
on top of a dark gray background (asphalt)? Then map that onto the
road surface. Again how do you get the map to be the right size and shape
to fit into 3DS?
4) If you used an opacity map, would you not see through the road
surface into oblivion? I'm looking forward to 3dsr2 and the additional
tutorials, on mapping I hope.
5) Would you suggest mapping the skid marks on just the required faces
or the whole road surface. The road surface might be nearly one square
mile?
Thanks again Martin for your help!!!……Rick
I like Jack's solution (the Yost Groupies). You will have to create the
animation of how the car moves and you can use this as a template in
animator pro to do an animated texture map. He's so smart!<g>.
Actually, if you can wait version 2 has some awesome tools which would help
you out. For example, you can get a ghost image of your car's wheels in the
2d shaper enabling you to make a flat skid path then clone that path to the
exact width you need. Then bring that shape into the 3d editor and have it
slightly above the road surface and use the animated opacity/texture map
technique. 3ds2 has some new mapping tools too, but you may need to use
Jack's technique to get the timing right since the car's speed is not
constant. As Gary would say "you figure it out","experiment","enjoy" and
"good luck", I wouldn't want to take away the joy of finding the complete
solution from you.<g>
Rick,
You could add a surface on the road surface with the full skid marks
mapped on. Then add a second surface on top of the skid marks with a repeat
of the road mapping. Then move the covering road surface along the road as
you need to uncover the skid marks. Haven't tried this but who knows.
Keith.
Picking up on your idea, Keith, you could use a matte object
(Modify/Object/ Attributes) and either link it to the car, or use Copy
Tracks to copy the car tracks to the matte object. (You'd need 3dsR2 to
most easily work the Copy Tracks.)
– J