Math Problem

[Blue]

Or rather, an expression problem.

I'm making a piston for a steam engine, and I need a sine function in order to govern how the piston moves via the rotation of a wheel, but I entirely forget how to do this sort of math, I haven't done it in three years.

 

DrivePiston Translate needs to move between 0.489 and -0.489

DriveWheel Rotation inputs a value in radial degrees.

 

I recall y=a*sin(mx+c) but don't remember anything about how that actually works or what the variables are in that equation apart from y and x.

[Alex Morton]

For your generic equation for a sinusoidal wave, a would be equal to the maximum displacement from the origin of the wave (ie. 0.489), m would be the a factor of compression (ie. if m=2 there'd be two sine waves in the space of one natural one), and c is where the curve would intercept the y-axis.

 

Hope that helps.

[J.C.]

Or rather, an expression problem.

I'm making a piston for a steam engine, and I need a sine function in order to govern how the piston moves via the rotation of a wheel, but I entirely forget how to do this sort of math, I haven't done it in three years.

 

DrivePiston Translate needs to move between 0.489 and -0.489

DriveWheel Rotation inputs a value in radial degrees.

 

I recall y=a*sin(mx+c) but don't remember anything about how that actually works or what the variables are in that equation apart from y and x.

 

Do you still need help with this one?

 

I would like in turn to pose a question for you, since you seem to be an accomplished animator and graphic artist: I recently downloaded the Source SDK and I feel a bit lost as to how to tackle this. Do you have any advice as to where to start? Or do you know of a set of tutorials I should follow?

 

EDIT: talked it over with Blue over PM.