Creating Videos

From K-3D

All animations are made-up of a sequence of still images (called "frames"). In the Unix tradition of DoOneThingWell, virtually all render engines are designed to render individual images, so K-3D renders an animation by running your render engine multiple times, once per frame, generating a sequence of numbered images. Since most RenderMan render engines only generate TIFF images, rendering an animation in K-3D will leave you with a directory containing a sequence of numbered TIFF images. Neither K-3D nor your render engine creates video files, you need external tools to do this.

Here is a list of resources to build videos out of image sequences:

• AnimMaker - Converts a set of images into a raw AVI file that can be processed further with other tools.

• ppmtompeg - Converts a set of images into an MPEG file. Part of the NetPBM tools.

• flip - Will load a sequence of TIFF files into memory and play them back at a target frame rate; optionally encodes a video using mpeg_encode.

There is a bash script that ships with K-3D 0.4 that is a convenient front-end to ppmtompeg. To use it, render the frames in your animation to their own, separate, empty directory. Assuming that K-3D is installed properly with the bin directory on your PATH, you may do

$ k3d-makempeg --play --loop /my/animation/frames myanimation.mpeg

... which will compress all of the images in the /my/animation/frames directory into the myanimation.mpeg file, playing it when complete.

• Windows 32 users can use VirtualDub to compile and encode frames from a series of JPEG still frames. They may also need a tool such as GIMP to prepare the .jpg files from the TIFF output of the renderer.