Camera rays only
The V-Ray help section states this about this little check-box in the modify panel: "The clipper will affect objects as they are directly seen by the camera, but they will appear unchanged to reflection/refraction/GI rays." I prefer the default of this unchecked as it seems to make most sense. I get unpredictable results if I tick it.
Depending on what result you want this check-box gives you the flexibility to control what is happening to the non-camera rays
Clip lights geometry
I've never used this option but essentially if checked your Clipper plane will not only clip geometry but it'll also clip the lights in your scene. I usually set my scene up to render correctly and then clip the geometry rather than clipping the lights as well. I prefer the control of turning lights on and off if I don't want them to affect my scene.
Clip the lights as well if you want to create a more bespoke look in your renderings
Use object material
If this checkbox is ticked then V-Ray will go ahead and fill in the cut object with the material that is applied to the cut object. If on the other hand it is not checked then the cut part of the object will inherit the material of the V-RayClipper object. For me it generally makes sense to use the objects material but there are occasions when you want the cut away to be a different material so this is a good option to have.
Let the cutaway parts of the objects inherit the material of their objects. This is my most favored but each to their own
Set material ID
If you feel a little limited by either using the material of the object or the V-Ray clipper object then make use of the ‘Set material ID' option. When enabled it lets you specify a face material ID. This is the ID that you can then put into a multi/sub object material to specify a different filled material. Really clever little addition to the toolset which gives us users even more flexibility about what the end product looks like.
Indulge in the flexibility of being able to apply different materials to the cut away parts of your models
Really simple, any object within your scene can be excluded from the effects of the V-Ray clipper. I'm really glad V-Ray decided to include this feature because it gives you the required control to be able to set up your cutaways exactly as you need them to be. Just click on the button and transfer any objects across that you want excluded. You can remove them again at any time if you change your mind. Naming your objects intelligently is recommended if you want to use this feature, especially on large and complex scenes.
Choose from the list what you want to exclude or include
All in all this is a great first iteration of the tool. V-Ray even improved it in version 3.1 by adjusting the underlying algorithm so it's clearly on their agenda. I can't say I've noticed any improvements to speed because of this but maybe it's just more stable, especially on complex scenes. Generally, I really like this tool and how reliable it is. Thankfully it's nothing like a Boolean tool which could crash on you at any time. Because it's a render-time effect it'll avoid those hair pulling situations of annoying crashes.
This is a great tool and one which I hope stands the test of time and gets improved on year on year
Top Tip: Animate the clipper
The clipper can also be animated which means that you can have a cut away which changes over time. Just set up some key position frames and render away! Experimenting with this can give some really cool effects.
Animate the position values of the clipper object to make your cut away more interesting in an animation
Top Tip: Use with Solid Works
Most of our clients who want cutaways are in the engineering sector. Simply import their Solid Works files into 3ds Max, set up the cut away and deliver gorgeous and effective renderings to a very happy client!
Importing Solid Works files for use with the V-Ray Clipper is a quick and easy workflow. You can do it with other file formats too
New and exciting features of V-Ray 3.0
V-Ray 3.0: New Features: New and Improved Shaders
V-Ray 3.0: New Features: V-Ray RT explained
V-Ray 3.0: New Features: Interface and Frame Buffer
V-Ray 3.0: New Features - Faster Rendering
Check out Paul's website
Take a closer look at V-Ray for 3ds Max
Grab a copy of 3ds Max Projects