Tomographic map of 3D data with a dimension described by probability distribution

I have a three dimensional data set. Two first components are the exact values of(X,Y) and for the third dimension I have a probability attached to each point for each given value of z between (0,1.5). for example P(x0,y0,z0)=0.24 and the probability is not necessarily Gaussian, it can be bimodal or trimodal distribution. I would like to make a two dimensional tomographic map (slices for example z=0.9 with width of delta_z=0.05) of my data but I do not know how I could involved probability distribution of points and estimate the weight each point gets regarding to its probability in each slice.

Could anybody describe whether there is a statistical solution to first put it in a frame work?