problem of projection

hi,

I have points in a virtual world.
All points are in a same plan (Z = cste)

I used canvas3D.getPixelLocationFromImagePlate(coord3D,coord2D)
to find the position of a point in image plate.

How can I found 3D position of an image plate point. if I use
canvas3D.getPixelLocationInImagePlate(coord2D,coord3D)
the point isn’t in z =cste plan but in z = 0 plan.

in fact, I search a matrix to project points between 2 plans
(in my case plan z=0 in plan z=cste)

Point (x,y,z =cste )----- getPixelLocationFromImagePlate —> Point(x’,y’,0)

Point(x’,y’,0) ------- ??? ------->(x,y,z=cste)

Thanks,
David.