Using Clipping
Overview
In this tutorial, you'll use learn how to use GlowWorm to render very
large, very complex scenes that Poser would otherwise choke on. Read this tutorial
through before attempting it.
Setting up your scene
Here's my scene. I know, I know--there's no way Poser would ever choke
while rendering that, but let's pretend that each ball has 8
million-billion polygons and enormously detailed texture maps.
What I want to do is render the scene in three layers: Foreground
objects in one, background objects in another, and then everything in
between. To do this, I'll add two of GlowWorm's Clipping widgets to the scene.
In Poser, go to the GlowWorm library folder. Add two Clipping
(scissors) widgets to the scene.
Every clipping widget divides the scene into multiple renders. If you
have one clipping widget, you'll get two renders, representing each
side of the widget. If you have two clipping widgets, you'll get three
renders: (1) Everything between the camera and the first clip, (2)
everything between the first and second clip and (3) everything after
the last clip.
You can have as many clipping widgets in the scene as you'd like. I've
placed one clipping widget between each ball.
So how do you know what makes it into each render? Here's a bird's eye
view of the scene.
Any object that ends before the clipping widget will be rendered in
that widget's zone. This means that, even though the ground plane is in
all three zones, it only appears in the third render--because that's
where the ground plane ends.
Let's look an another example with an object that breaks a clipping
widget's boundaries.
Here, the box starts in the first zone, but since it ends after the
first widget, it gets rendered with the second zone objects. This isn't
the ideal way to handle things, but, due to technical limitations, it
was the best option available.
Shadows in clipped renders
The clipping widgets are in place; the scene's setup; we're good to go,
right?
No--if you're rendering with shadows, you need to consider what's going
to happen with them. There are two easy work-arounds:
- Render a shadow pass,
without using the clipping widgets. This is recommended for scenes with
complicated shadows.
- Put a shadow-catcher
under each ball. You can add a plane under the first and second balls
that will fit entirely in the zone, and then check the Shadow_Catch_Only box in the plane's
materials. That way, the shadows that would normally be cast on the
ground will show up in your render. You don't need to add a shadow
catcher for the last ball, because the ground will render with it. This
is recommended for scenes with simple shadows.
Since the shadows in this scene are going to be pretty simple, I'll go
the shadow-catcher route.
Setting up the render job
In Poser, launch GlowWorm from the library. Click the "Add File" button
and select your scene.
Unless you're doing an animation, be sure to change the Output Frames
to "Current". Set other properties as desired.
You can have whatever render passes you like. GlowWorm will
automatically cut up and render any scene that contains Clipping
widgets.
Compositing the clipped renders
Here are the three clipped images from just doing a normal render. Each
one of them has an alpha channel that can be used to cut it out.
After that, it's just a matter of putting one layer on top of the other!
