Question: 3d plot with many unknowns (please help!)

I have implemented an economic model into Maple with the objection to plot a 3d graph from the final equation in order to visualize the effects these three parameters have on each other. But I don't no how to do it. Here is the equation I want to plot;

The_equation := [-(u+delta)*[(1-`c`)*(`c`-`c2h`-`t`)]+[(1-u)*(1-`q`^2)*[1/((4-`q`^2)*(1-`q`^2))]^2*[(2-`q`^2)*(`theta`-c2l-`t`)+[-`q`*(1-`c`)]]^2-(1-u)*(1-`q`^2)*([1/((4-`q`^2)*(1-`q`^2))]*[(2-`q`^2)*(`theta`-`c2h`-`t`)]+[-`q`*(1-`c`)])^2]]

It consists of 7 unknows. Now I want to set the unknowns u, delta, q and theta equal to a constant and make a 3d plot with respect to c, c2h and t. I have already tried to substitute the first parameters for some constant, for instance 0.5, and then plot, but this does not work.  How do I proceed? I have possibly made many different mistakes since this is the first time I work with Maple, so any advice will do!