Help! Math problem in mapping Created 16 years ago2007-05-05 00:01:42 UTC by -japz-

I'm currently making a test for a ferris wheel. But I can't get the speed of the gondola right. the gondola gets slower than the ferris wheel, and I have a hard time getting it right. Could you help me by giving me the formula/operation? Here's the problem:

http://www.geocities.com/appledjapz/untitled.JPG

sorry, don't know how to post the pic, IMG SRC is isn't working

My brain is shot at the moment. I'd suggest posting it on a maths or physics forum, they usually crank an answer out quick-smart.

the wheel is rotating at 21 units/second? i suppose that would be the angular velocity of the wheel in degrees per second?
check that a speed of 360 makes the wheel rotate 1 complete turn in 1 second. if it does,
then the speed of the car should just be 21, with the origin at the same place as the wheel.
also check if the size of the wheel makes a difference to how much it rotates. if you double the radius of the wheel, does it still rotate at the same speed? do some experiments with these and tell the results here. even a physics expert couldnt help you without knowing what value 21 actually represents.

I'd say that if the whole track around the wheel is r2*pi =~ 3141.59, and angular velocity of the wheel is 21 degrees per second, then the velocity of gondola should be 3141.56/21 = ~149.6

You won't get it exactly right tho, because those are rounded up numbers. But it shouldn't be very noticable.

Oh yeah, and i'm presuming you're using func_train to navigate the gondola around.

It would have to be exact.. which is probably impossible with the engine. If it's 'close enough' it will become more and more out of line with the frame as time progresses.

Yeah, it's impossible to time things EXACTLY right in this engine... just doesn't work that way, it's far too crude a technology. Plus, even if you could get the timings correct, func_trains tend to be very imprecise when they move, and can get jerky, or get offset easily. It's just unpredictable.

149.6 would be the seconds needed for a full rotation, not the speed of an outer point.
So, if it takes 149.6 seconds to rotate 360 degrees, it will move at 360/149.6 = 2.40642 degrees per second. That would be the rotating speed.

Thank you guys for help, but the operations that Cleric cited did not work. i've also tried to work out the radius and speed of the ferris wheel in Absolute Redemption with r2*pi/speed-of-rotation but it didn't have the same values the trains & wheels had.

What about the speed I suggested?
Didn't you try that one out?

Calllllm down Kasperg,
Your idea is important too!

Thanks Kasperg for your help, but i haven't tried your speed yet. I want you guys to help me out by giving me the mathematical solution.. I want to know how the Maverick guys did out their ferris wheel perfectly..

DO NOT... Start a thread saying "Help!"

please...

Yeah, what else would you be looking for? :

Worse is "Help please!" or "I have a problem!".

I want you guys to help me out by giving me the mathematical solution.

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if the whole track around the wheel is r2*pi =~ 3141.59, and angular velocity of the wheel is 21 degrees per second, then the velocity of gondola should be 3141.56/21 = ~149.6 (time it takes to do a full rotation)

So, if it takes 149.6 seconds to rotate 360 degrees, it will move at 360/149.6 = 2.40642 degrees per second

I don't know if we can get more mathematical than that

Actualy very simple mathematics. And you wont need to be that accurate to decimals, you only have to be rounded of to about 2 or 3 decimals.

The point is though, it'll go further and further from its intended position the longer it goes, if it's off any. And no, I don't think GoldSrc does support that many decimals.

If all else fails, just decompile the BSP and see how they did their entity setups. It doesn't sound complex, but I suppose it could be.

I decompiled that map and played with it.. Maybe I should give the specs of the ferris wheel. It might take longer coz the PLDT (the provider for phone and Internet) cables was still down at our town.

mega sigh, the gondolas will not travel in a circle, that maths is quite useless.