I remember using the original version it worked well it wil be nice to have another tool on the tool belt.....now if I can just find my pants ..(says john trying to be funny like Vern)
I tried adding the light to a model in the model window then adding the rotoscope in the chor and it did not work, But using a separate light and attaching the light to a model in the chor with a constraints it worked fine using the image you posted
try the light in an empty chor if you have it setup correctly you should see t on the ground if you aim it there... then if it works there.... trouble shoot in the other chor to see why it does not show..by folowing do you aimed at...
reasonable water can be made with a simpl;e combiner use fo both color and displacement aniated in the chor
here is a sample that is a lttle too quick
WATERY.mov
project v15c
WATERY.zip
Foe the darksim water material once you apply it and adjust the speed it animated as it renders
here is a quick sample on which i applied the ocean material to a sphere and rendered with the default settings
simwaterocean.mov
the other is an old post from my now defunct web site showing water and ice darksim materials
watersim.mov
there was just a recent post showing how o use the plugin recently use the search in the upper right to look for it
what you could also do is after you build a tree select it and do a copy flip attach and you can then adjust the mirrored model on the bottom for the roots
quick example
not sure what you are trying to do but here is something I threw together
liq.mov
liq.zip
turned the emission rate on 300 and off 0 in the chor and I have the liquid bouncing off the target