From kragen@dnaco.net Fri Jul 31 11:56:30 1998 Date: Fri, 31 Jul 1998 11:56:29 -0400 (EDT) From: Kragen To: fractint@lists.xmission.com cc: GregJ56590@aol.com Subject: Re: (fractint) Heightfields In-Reply-To: <60dbcc90.35c0f274@aol.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Keywords: X-UID: 922 Status: O X-Status: On Thu, 30 Jul 1998 GregJ56590@aol.com wrote: > How does one create heightfields for ray-tracers like POV-Ray using Fractint? > > I only seem to be able to make images with 256 colors. When I open these > images in a paint program, the histogram of their color distribution shows > that they are not a continuous distribution. 256 colors is probably good enough most of the time. But the default settings yield a very steep slope away from, say, the Mandelbrot lake. > I've seen some web references to people using Fractint to make heightfields > for POV-Ray. Try some of the following: - Use the distance estimation method. - Set your bailout value to something enormous. - Use a outside-coloring method other than the iteration number at bailout, which is the default. (256-way decomposition is pretty cool. The surfaces it yields are very discontinuous, which may not be what you want.) - Make sure maxiter is at least 255 if you're coloring according to the default method. (More than 255 might produce wraparound near the lake, where you follow a gradual slope upward to 255, then precipitously drop down to 0, then go up again to the lake.) - Use a different inside-coloring option. - Use a hicolor or truecolor video mode so you can have more than 256 levels. (They'll look better as heightfields than on the screen, I think.) > Some of you on the list may remember that a few months ago, I > complained about the difficulty (impossibility) of getting true RGB, or even > true 256 Gray images out of Fractint. Why can't you get 256-gray images? > The fact that people are using Fractint > to make heightfields makes me wonder if I did not ask the correct question. I'm puzzled. > Perhaps I am so dense as to need to be shown the exact keystrokes. Maybe so, or maybe not. Do my suggestions make sense? Kragen (it's been years since I did heightfields with fractint, so I may be spouting nonsense)