Friday, May 11, 2012

Photoshop in Blender, Part 2: Transparency

In Part 1 of the Photoshop in Blender tutorial series, I introduced you to Blender’s compositor node setup. In this tutorial, we are going to combine an image that I took with my digital camera - an antique Vermont Railway locomotive, displayed at the White River Junction, Vermont, railroad station - with Suzanne in front of it. You’re looking at the final result. We’ll discover how transparency works in Blender, and why understanding and controlling image transparency, and the concept of the alpha channel, which is crucial in combining images in the compositor.
We’ll also pretend that we are creating this image for HD TV. In this case, the resolution of the image I took was 2592 x 1944 pixels.

Actually, when video is edited, it’s basically a sequence of images. Each image is called a frame. So we’re just editing one video frame. In later tutorials, I’ll show you how to edit videos with full motion, but that’s getting ahead of our story. In this tutorial, I will introduce a number of composite nodes, the viewer node, the Mix node, the Alpha Over node, and the Scale node, to accomplish the job. I hope you will become more comfortable with using Blender’s composite nodes after watching this tutorial.