Rendering and Compositing - Animating with Blender: How to Create Short Animations from Start to Finish - page 295

3. The RenderLayer Layer buttons (See? The names are getting silly.): This set of layer but-
tons controls which of the available, active layers will be included in this particular render-
ing group. The result of an Input node set to this RenderLayer will be only the objects on
the layers indicated on this part of the panel. Layers that are activated on this portion, but
that are not active on the overall Scene Layer buttons, will not render . Even though the
RenderLayer settings allow it, the Scene-level Layer buttons have not passed the informa-
tion for those objects along for render preparations in the fi rst place. This is where things
start to get wacky. Active objects in a RenderLayer group will not receive light from lamps
that are not on active layers in the same RenderLayer group, regardless of the lamps' par-
ticular Layer setting in the Lamp buttons . However, lamps and objects that are on an active
RenderLayer layer can receive shadows from objects that are on inactive layers for this par-
ticular render group. Figure 15.22 shows a simple scene consisting of a lamp, a monkey,
and a plane. The lamp is on layer 2; the plane on layers 1 and 2; the monkey on layer 1.
Figure 15.23 shows the result of a RenderLayer with only layer 1 active. Figure 15.24 shows
the result of only activating layer 2. Note that both layers 1 and 2 must be active in the
overall Scene buttons to achieve this result.
4. Render Features: This controls which portions of the renderer are used. Generally, you will
leave this alone unless you specifi cally need only, say, Halos or Strands to appear in their
own input in the compositor.
5. Lamp and Material Overrides: The
Light: fi eld receives the name of a
previously created Group of Lamp
objects. When a valid group name
is entered, only lamps from that
group are used when evaluating this
RenderLayer. Likewise, when a valid
material name is put in the Mat: fi eld,
that material is used for all objects
appearing in the RenderLayer.
Figure 15.22 A basic scene
Figure 15.23 Rendering a RenderLayer using only Layer 1. The lamp is on Layer 2, so the Layer 1 object is not lit