Fast Depth of Field

Overview

In this tutorial, you'll use GlowWorm, Poser 6 and compositing software, such as Photoshop, to create depth of field with good results and no long render times.

Setting up your scene

In Poser, go to the GlowWorm library folder. Add the DepthCue_Start (S) and the DepthCue_End (E) widgets to the scene.

You should position the S widget where you want objects to be sharpest. Everything between the S widget and the camera will be in focus.

You should position the E widget where you want everything to be blurry. Everything after the E widget will be completely out of focus.

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'll need to have two render passes:

The ff Pass

This pass is GlowWorm's Normal Render preset. You can do without this pass if you already have a render of your scene on hand, or if you want to composite other passes.

The zb Pass

This is GlowWorm's Depth Mask preset. It's a select pass with ambient.

Hit GlowWorm's Render button to render the job.

Compositing the Passes

1) Open up the depth mask in Photoshop.

2) Select All (Ctrl+A) and Copy (Ctrl+C).

3) Close the depth mask and open the normal render.

4) In the Channels palette, you should see the RGB channels and an alpha mask (Alpha 1). The alpha mask is created by Poser; it's a cut-out of the objects in the scene.

Click the "New" button to create a new alpha channel (Alpha 2). Paste (Ctrl+V) the depth mask into Alpha 2.

If you haven't played with alpha channels before, they're a very cool tool. An alpha channel is, essentially, a stored selection. You can hold Ctrl and click on an alpha channel to load its selection.

5) Select the RGB channel to go back to the normal image.

6) Ctrl + click Alpha 2 to load the depth selection. Now "jump" the selection to a new layer by hitting Ctrl+J.

You should now have a cut out of the distant objects (Layer 1) over your normal render (Background).

7) Use the Gaussian Blur filter on Layer 1 to your liking. I used a setting of 5.6 pixels.

8) Select the Background layer. Go to Filter > Blur > Lens Blur. Here are the different controls that you should be most concerned with (feel free to experiment with the other settings).

Under "Depth Map"...

Source should be set to use your depth channel (Alpha 2).
Blur Focal Distance controls where the focus is in the depth channel. Adjust this until the region that you want to be in focus is in focus.
Invert should be checked.

Under "Iris"...

Shape changes the sample area of the blur. I used "Triangle."
Radius changes the size of the blur.

Hit OK to apply the filter, and there you have it--a quality depth of field without the steep render time, and one that you can adjust with real-time feedback.