- [Instructor] In this exercise,
we're going to walk through using the clipper tool
that is essentially V-Ray's way of creating render time
cutaway effects.
Now, SketchUp users new to V-Ray
may wonder why we don't just use
SketchUp's own section plane tool,
given that it is, after all, very easy to work with.
Well, we could do that,
and so if we just apply the section plane to our butterfly,
position it so that we get an interesting intersection,
and then take a render,
we can see that everything works just as we would expect.
However, this kind of planar cutaway,
albeit in various orientations,
is pretty much all that we can do
with the section plane tool, which is fine
if this type of cutaway is all that we need.
The V-Ray clipper tool by comparison though
is capable of bringing
a little bit more to the table for us.
To demonstrate, let's delete the SketchUp section plane
and then, after drawing out a polygonal shape
underneath our butterfly geometry,
extrude that up,
and then triple click in order to select all of the pieces
so that we can come to the Edit menu
and turn this into a group,
seeing as being a group or component
is a prerequesite for geometry
that we want to turn into a clipper object.
Let's just position this
so as to create an interesting effect if needed,
and then from the V-Ray objects toolbar
click on the Mesh Clipper option.
Now, whilst we see nothing happen in the view port,
as soon as we hit render,
we see exactly what the clipper object is capable of doing.
And, of course, if we copy
and paste this a couple of times,
and then place the geometry in different areas of our mesh,
we again, at render time, see that we are able
to create all kinds of interesting effects.
In the Geometry tab of the Asset Editor,
we gain access to the few control parameters
that are available for the clipper,
with the Mode drop-down
allowing us to switch between subtraction,
as we see in our render here, and intersection behaviors,
although intersection, in this particular case,
would just give us a blank render.
Just below that, we can turn off
the Use Object Material switch,
and instead choose to cap our subtractions
with any material currently found in the scene.
In Options roll-out, Affect Light is an interesting control
in that, if we were doing a planar cutaway of a building
going from exterior to interior, say,
having this enabled would allow light
on the outside of the building
to penetrate through the clipper object
and add their light to the interior,
whilst having it disabled doesn't allow light in.
The Camera Rays Only option works in a somewhat similar way,
only this time for the camera and not light and shadow rays.
With it enabled, the clipper will affect objects
as they are seen directly by the camera,
but it leaves them unchanged
so far as things like reflection, refraction,
and GI rays are concerned.
Whilst the final option, Clip Light Geometry,
lets the clipper cut into light objects if required,
such as, say, a mesh light in the scene.
A couple of things to be aware of here,
as noted in the V-Ray help,
that one, the clipper works best with closed objects,
and that, two, currently the V-Ray clipper
may produce artifacts if there are overlapping triangles
in the scene, regardless of whether
they are part of the same objects or not.
So, just be aware of those two possible problem areas.
The Mesh Clipper tool though,
whilst simple in its execution,
does add a welcome set of easy-to-use options
that I'm sure V-Ray for SketchUp users
will put to very good use.