Image Panel Widget.

Uses Motif Widgets ( Choice, Toggle, Scale, Push ) to adjust properties of appearance/style of the output image.

In Ribbons 3.0, invoked from Edit in Menubar or ALT-j

If an existing image file named `background.rgb' is present, it will be the background.

Use ``Outline Image'' in Menubar View to outline the primitives.
May also use ``Save Image'' in Menubar File to set the filename to be saved.
Critical! Hit ``PrintScreen'' key to actually save the image, or the ``Pause'' key to cancel the save.

Widget Name (Widget Type) --- description of function

Image Type (Choice)
- WYSIWYG -- (default) saves the screen image.
- Black&White -- processes screen to give the impression of an artist's line drawing with cross-hatching for shading and depth-cueing.
- Blend Inten -- the Black&White image is blended with the grayscale version of the WYSIWYG image. Slider below controls amount of blending.
- Blend RGB -- the Black&White image is blended with the normal color image of the WYSIWYG mode. Slider below controls amount of blending.
- SuperSample -- use off-screen rendering to render the WYSIWYG image larger than screen resolution (Warning - see notes below).
- SuperSamp-BW -- use off-screen rendering to render the Black&White image larger than screen resolution.
- A.StereoGram -- process image to produce an auto-stereogram.
AntiAlias Passes (Choice)
-- Set number of imaging passes for full-screen antialiasing. Gets rid of the `jaggies'. Can use with super-sampling, but slow.
SuperSamplingScale (Scale)
-- set the scale factor for off-screen rendering.
-- Note: this may fail. Save settings before you try. See notes below.
Image Format (Choice)
-- either SGI (*.rgb) or the Tagged Image Format (*.tiff).
-- Note: if SuperSampling (or a DEC alpha), can only be TIFF.
0 RGB--B&W 1 (Scale)
-- set the scale factor for blending Black&White and WYSIWYG images. Used if ImageType is BLEND.
BW 'Shadow' Color (Choice)
-- select a color to be given special cross-hatching in the Black&White style. The default is gray (colorindex=9).
Mock Line Drawing (Toggle)
-- removes all `shading'. Makes all colors (except gray and black) white. Should turn on outlining. Be sure to antialias if saving.
Scale BG Image (Toggle)
-- force the background image to be scaled to the current window. This image must be in the current directory and named `background.rgb'.
BW.read (stdin) (Toggle)
-- change parameters for Black&White rendering. Prompts at the terminal for values that won't mean anything to you, unless you read Goodsell/Olson paper (see Notes below).
Save Image (Push)
-- set the filename to be saved (then hit PrintScreen key).
-- Same as the selection from the File menu (or Alt-i).
Close Panel (Push)
-- dismiss the panel
Panel Help (Push)
-- show this help screen

Hints:

If you have a file named 'background.rgb' in your directory, it will serve as the background. It is placed at the far clipping plane. Will slow you down if you toggle on scaling of this image to the window.

For SuperSampling, the scale is for the current window. Values between 1-4 are allowed. 2 gives ~300 dpi resolution. 4 would give 600 dpi, but I can't do it on my machines with a full screen (?).

This works on my O2:

 ribbons -n yourmodel -w 1000,800
 hit alt-j to invoke ImagePanel
 choose 'SuperSample' from ImageType (upperleft)
 choose Save Image ( Note: forces a *.tiff == TIFF file)
 hit PrintScreen to actually save and say a small prayer
 imgworks yourfile.tiff  (it should be ~2000x1600)

Then maybe try to make even bigger with -w option! (or smaller if it crashes, see Bugs below). Also see other types of and general information on Control Panels.

Notes:

The Black and White code is based on an algorithm from a Japanese group, implemented & published (&copied by me) from: Molecular Illustrations in Black and White David S. Goodsell and Authur J. Olson J.Mol.Graphics (92).

We get autostereograms in the funny papers. Looks like random noise, but 3-D picture hidden within. Algorithm for drawing an autostereogram: H.W.Thimbleby, S.Inglis & I.H.Witten (Oct94) Computer, p38-48.

SuperSampling based on code kindly supplied by Jason Freund at SGI (formerly at UAB). All SGI computers that support its offscreen 'P-buffer' OpenGL extension are supposed to make at least 2000x2000 images, but...

Bugs:

SuperSampling might dump core if not supported on your computer. (i tried to put in the checks as explained in the man pages). More likely it will simply fail if you attempt to create an image larger than the new SGI Pbuffer extension can handle. If so, will spit out this:

 > X Error of failed request:  BadAlloc (insufficient resources ...)
 >   Major opcode of failed request:  141 (GLX)
 >   Minor opcode of failed request:  17 (X_GLXVendorPrivateWithReply)
 >   Serial number of failed request:  0

All SGI computers that support this are supposed to make at least 2000x2000 images, but... From their man page: MACHINE DEPENDENCIES
The SGIX_pbuffer extension is supported only on RealityEngine, RealityEngine2, and VTX systems, on InfiniteReality systems, on High Impact and Maximum Impact systems, and on O2 systems.

Ribbons User Manual / UAB-CMC / carson@cmc.uab.edu