Dynamic roll centers-- Check :-)

In place and working great with the appropriate jacking forces. They move around correctly and are calculated in real time from the suspension geometry :-) Look closely for the red and blue lines; their intersections show the roll centers. http://performancesimulations.com/images/RC01.JPG The car visibly lifts when you put these high enough, and will overturn if you go too crazy with them. There's a cool sort of "pop" effect when you come off the brakes and rapidly hit the throttle while cornering. Hard to explain, but it looks pretty cool :-) Tuning the cars is becoming progressively more difficult, but I'm liking that! :-D Todd Wasson --- Performance Simulations Drag Racing and Top Speed Prediction Software http://PerformanceSimulations.Com My little car sim screenshots: http://performancesimulations.com/scnshot4.htm

On 30 Dec 2002 05:36:52 GMT, [email hidden] (J. Todd Wasson) wrote: >In place and working great with the appropriate jacking forces. They move >around correctly and are calculated in real time from the suspension geometry >:-) Look closely for the red and blue lines; their intersections show the roll >centers. > >http://performancesimulations.com/images/RC01.JPG Hehe, looking cool, Todd! Nice work. :) Ruud van Gaal Free car sim: http://www.racer.nl/ Pencil art : http://www.marketgraph.nl/gallery/

Whee! Nice stuff Todd. How's the physics calcs affecting the cpu? A friend of mine is using ODE to simulate his unequal-length double wishbone suspension but it's hitting the cpu very hard at just 120 Hz. Ignoring springs for now, he has an arrangement in ODE using "chassis-hinge-bar-balljoint-upright" (that's the upper wishbone simplified using the hinge so only one bar is needed). Lower wishbone is the same, and then there's a control arm "chassis-ball-bar-ball-upright" on each wheel which is static at the back and used as a steering input at the front. This gives 2 hinges and 4 balls per corner, so 8 hinges and 16 ball joints total. Needs some optimising I think. Are you using ODE? Or your own custom supercool solution? :0) Jim "J. Todd Wasson" <[email hidden]> wrote in message news:[email hidden]... > In place and working great with the appropriate jacking forces. They move > around correctly and are calculated in real time from the suspensiongeometry > :-) Look closely for the red and blue lines; their intersections show theroll > centers. > > http://performancesimulations.com/images/RC01.JPG > > The car visibly lifts when you put these high enough, and will overturn ifyou > go too crazy with them. There's a cool sort of "pop" effect when you comeoff > the brakes and rapidly hit the throttle while cornering. Hard to explain,but > it looks pretty cool :-) > > Tuning the cars is becoming progressively more difficult, but I'm likingthat!

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> :-D > > > Todd Wasson > --- > Performance Simulations > Drag Racing and Top Speed Prediction > Software > http://PerformanceSimulations.Com > > My little car sim screenshots: > http://performancesimulations.com/scnshot4.htm >

>Whee! Nice stuff Todd. > Thanks :-) >How's the physics calcs affecting the cpu? There's very little difference. It runs about the same as it did without it. Visibly, I can't see a difference in the frame rate, and this is on a 333mhz laptop I'm running here. Even at 300hz, everything's nice. Basically, it's like adding around 3-5 extra ground triangles to the track and that's about it. No big deal. Sounds like your friend has quite a system going, but yeah, that type of approach is going to really eat up the CPU in a hurry. >This gives 2 hinges and 4 balls >per corner, so 8 hinges and 16 ball joints total. Needs some optimising I >think. Ouch.. Expensive, but I have to admire his tenacity to go to that extent for it :-) >Are you using ODE? Or your own custom supercool solution? :0) No libraries here except OpenGL for graphics. This is my own little approach :-D Todd Wasson --- Performance Simulations Drag Racing and Top Speed Prediction Software http://PerformanceSimulations.Com My little car sim screenshots: http://performancesimulations.com/scnshot4.htm

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>Hehe, looking cool, Todd! >Nice work. :) > > >Ruud van Gaal >Free car sim: http://www.racer.nl/ >Pencil art : http://www.marketgraph.nl/gallery/ >

Thanks, Ruud :-) I'll have to try to catch up to you in the graphics department soon 'cause mine are still looking pretty rough.... Maybe in 5 years if you stop working ;-) hehe Todd Wasson --- Performance Simulations Drag Racing and Top Speed Prediction Software http://PerformanceSimulations.Com My little car sim screenshots: http://performancesimulations.com/scnshot4.htm

"J. Todd Wasson" <[email hidden]> wrote in message news:[email hidden]... > Sounds like your friend has quite a system going, but yeah, that type of > approach is going to really eat up the CPU in a hurry. Yep, I've been betatesting for him and although he's getting 50 fps on his super duper computer, I can't actually run the sim as fast as real time. Zero fps. :0)

>Yep, I've been betatesting for him and although he's getting 50 fps on his >super duper computer, I can't actually run the sim as fast as real time. >Zero fps. :0) > > Zero?? Hey, that's not too bad... ;-P Todd Wasson --- Performance Simulations Drag Racing and Top Speed Prediction Software http://PerformanceSimulations.Com My little car sim screenshots: http://performancesimulations.com/scnshot4.htm