Friday, February 3, 2012

Subway Station - Compositing

Here's the latest render of my subway scene. I'm beginning to be pretty happy with the result. I added some compositing to it. The people were added in Photoshop, but the glares and other post processing touches were all done in Blender. The defocus was added as part of the compositing. To do this, you blur the image using the Z-depth map. In order to access the Z-depth information, you need to check the Z option in the Layers panel on the Render tab (see Figure 2).

Figure 1. Notice the depth of field effect, plus the different glares added
in the Compositor. Also, I added a slight vignette effect.

Figure 2. Checking the Z option in the
(render) Layers panels allows you to use the
Z-depth info—that is, the distance from the camera
expressed as a grayscale gradation.
Figure 3 shows what this looks like (untouched).

Figure 3. The information about Z-depth in grayscale representation.

Figure 4. This is the node setup I used here to add depth of field to the scene.
I tried to achieve a very subtle effect, because I feel that overdoing it ends up
making the whole scene look like it's really tiny (tilt shift effect).
The grayscale information of the Z map is fed into the Size slot of
the Blur node—that is, the blur gets applied 100% to the white areas in the image,
and the black areas get zero blur.