Here is stuff I have written down on how springs work. Don't ask me what a "logarithmic impulse formula" is for. I don't know. I just copied down equations that looked important.
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SPRINGS
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http://www.pcug.org.au/~apurdam/doublespring/doublespring.html
two masses, connected by one spring:
M1, M2 = masses
k = coefficient of stiffness of the spring
x1, x2 = the displacements of the masses from their positions of equilibrium
x1'', x2'' = the acceleration for M1 and M2
r = viscous damping
x1', x2' = velocity of masses (from previous frame?)
x1''= k / (M1*(x2-x1)) - r*x1'
x2''= k / (M2*(x1-x2)) - r*x2'
misc notes:
Logarithmic Impulse formula.
Impulse = Log(RestSpan) - Log(CurrentSpan)
Note: this is a different from the usual linear spring formula which is taught in physics classes. With the logarithmic formula, it should be impossible to completely compress the spring. It also means that springs that have long rest lengths vibrate much slower than short ones.
--------
SPRINGS
--------
http://www.pcug.org.au/~apurdam/doublespring/doublespring.html
two masses, connected by one spring:
M1, M2 = masses
k = coefficient of stiffness of the spring
x1, x2 = the displacements of the masses from their positions of equilibrium
x1'', x2'' = the acceleration for M1 and M2
r = viscous damping
x1', x2' = velocity of masses (from previous frame?)
x1''= k / (M1*(x2-x1)) - r*x1'
x2''= k / (M2*(x1-x2)) - r*x2'
misc notes:
Logarithmic Impulse formula.
Impulse = Log(RestSpan) - Log(CurrentSpan)
Note: this is a different from the usual linear spring formula which is taught in physics classes. With the logarithmic formula, it should be impossible to completely compress the spring. It also means that springs that have long rest lengths vibrate much slower than short ones.