Import images into CavePainting

You can add custom color palettes, slides, paint stroke patterns, or paint stroke masks to CavePainting simply by loading image files into the program. In order to work, though, they need to be in a particular size and format, and have a particular sort of name. Loading them into the program is pretty easy, but the first time you do it you need to perform an extra setup step.

Image Format

All images used in CavePainting must be JPEGs (extension .jpg). In the filename patterns described below, an asterisk (*) indicates any text you want.

Color Palettes

Custom color palettes must be 512x512 JPEGs with a filename of the form color-swatch-table*.jpg. The image should be full of vertical stripes, but they may be as narrow as you want, even one pixel wide.

Slides

Slides, also known as "billboards", are flat images that you can place in virtual space like floating pieces of paper. Each slide depends on two files, a picture and a mask, which must be the same size and have matching filename patterns.

File	Name Pattern	Size	Function
Picture	slide*.jpg	64x64, 128x128, 256x256, 512x512...	The picture on the slide.
Mask	alphamask*.jpg		A black-and-white image matching the picture. The picture is visible where the mask is white, and it's transparent where the mask is black.

Stroke Patterns

See the CavePainting introduction for information while this document is under construction.

Stroke Masks

A stroke mask applies a pattern of transparency to a brush stroke. Stroke masks are black-and-white images; where the mask is white, the stroke is visible, and where it is black, the stroke is transparent. The vertical direction in the mask image is aligned with the direction of the stroke — that is, a mask that looks like horizontal stripes will result in a brush stroke with stripes across it, whereas a mask of vertical stripes will result in a brush stroke with stripes along its length.

Each palette of stroke masks contains 16 individual masks, each of which is 64x64 pixels. The image for an entire palette of stroke masks has all of the square masks lined up in a single row, resulting in a 1024x64 black-and-white JPEG. The filename format for stroke mask palettes is brushtips*.jpg.

Loading Images

To import images into CavePainting, log into any of the black computers in the Cave room. They are named dev1 through dev4.

Setup

You have to do a little bit of setup the first time you import images. After that, you should be able to just follow the steps in the next section.

1. Right-click on the desktop and select "Open Terminal".
2. In the window that opens, type

   /share/cs137/cs137-init

   and hit enter.
3. Close the window.

This step creates a folder on your desktop called "CavePainting Directory". This is where all your files go. If you ever don't see this directory, just repeat the steps above.

Transferring Files

To load files into CavePainting, you need to get them onto one of the black computers in the Cave. You can do this by plugging a key drive into the front of the computer, emailing files to yourself, uploading files to some server, or any other way you choose. Whatever you do, download the files to your desktop, and then drag-and-drop them into the folder called "CavePainting Directory" that you see on the desktop.

Be sure to log out of the computer once you're done.

That's it! The next time you open up CavePainting, your new images should be enabled. If you don't see them in the palette where you expect them, try pushing the button on the non-brush controller to switch palettes.

Using Images

For instructions on how to use slides, stroke patterns, or stroke masks, see the Use Cavepainting HOWTO.