Displacement and broken edges
I was working on a project where I needed to use some displacement maps on a material. So, I was setting up the material in the matlab for use in my scene when I noticed the tearing edge effect my material was having on the test object.
To make a long story short, I didn't notice that I had set the Max. Displace value too high for our 3dsmax material lab test object. It's currently configured for 4" and that's too high for this particular mesh. So, if you're finding the edges tearing on your meshes when using displaced materials, keep an eye on your max. displace setting to make sure that's not the culprit.
Here are some images to help illustrate this issue. The first image shows what happens if the current values are used. NOTE: I also decreased the Max. Subdivisions to 256. I did this because the mesh is so heavy mental ray shouldn't need to subdivide much. That being said, I had it originally configured at 1k in case anyone tried to displace hair/grass and needed the extra details.
(click image to enlarge)
In the second render I've adjusted the max. displace value down to a more reasonable value (1") and doing so helps remove the edge tearing.
(click image to enlarge)
I could have reduced the max. displace value further for this particular material, but I figured I'd mention to set it at 1" to cover some extreme displacement scenarios. If you're just midly displacing something like I am here, .25" or .5" would probably work fine.
