Here is quick tutorial for creating realistic climbing ivy on wall using Skatter and VRAY 3.6.
Step 1 - find an ivy leaf you like. I used this one from 3D warehouse. I changed the component Axis to the base of the stem so that’s where it will “attach” to the wall from now:
Step 2 - Create a surface group on your wall where you want your Ivy to “spread”:
Step 3 - Dial in your Skatter settings. I used WrapUV and adjusted so that they point down just a bit like they’re hanging and then used the Altitude Range and Top Falloff to taper the density as it moves away from ground. Then applied some random rotation, scale and mirroring to loosen it up a bit more:
Step 4 - Render Result:
And lastly, copy settings from test model to whole building and see how it looks…not perfect, but not bad either for 10 minutes of tinkering…Now I am no longer limited to just what 3DWarehouse has to offer with regards to adding vines and ivy to my models/renders 
