How to create a 2D waterfall plot?

I would like to create a 2D spectral density waterfall plot. I imagine it would be easier to use the waterfall function somehow or even to create my own code for it by somehow using the waterfall function to create an array which displays horizontally along the y-axis, and then either shifting that row down or just plotting the new row under it. Is there a way to save the waterfall data into an array? Or a way to plot the new waterfall data with an offset on the y-axis?

the waterfall data is an array called 'sweepData' which is updated in a loop which I would like to be appended to the waterfall graph in each loop

Attached is a picture with 1 plot of the waterfall data, I just need to keep plotting the new data under it

Code:

subplot(3,1,3)

spec_dens = waterfall(sweepData);

xlabel('Frequency (MHz)')

ylabel('Sample Number')

title('Waterfall (Spectral Density Graph)')

view(0,90)

xlim([0 numSamples])

ylim([0 numCapture])

set(gca,'Ydir','reverse')

[Veronica yep]

sorry i should say, the data, 'sweepData' which is used in the waterfall function is just an array of power values of corresponding frequencies