x <- y <- seq(-10, 10, 0.5)
f <- function(x,y) { r <- sqrt(x^2+y^2); 10 * sin(r)/r }
z <- outer(x, y, f)
for(t in 0:100) persp(x,y,z, theta=30+t/2, phi=t/2, expand=1/2, col="lightblue")