Opening Ultra Fractal 4 files with Ultra Fractal 3

Most parameter sets and fractal files written by Ultra Fractal 4 will open fine in Ultra Fractal version 3.05. This topic describes the exceptions.

Differences between Ultra Fractal 4 and Ultra Fractal 3

The basic parameter file and fractal file format has not changed in Ultra Fractal 4. Apart from animations, you can generally open Ultra Fractal 4 files successfully in Ultra Fractal 3.

However, to support animations with repeated rotations, Ultra Fractal 4 removes several restrictions on parameter ranges. In version 3, the Rotation Angle on the Location tab was restricted to [-360..360], the index of gradient control points to [0..399], and the gradient rotation to [-200..199].

All of these restrictions have been removed in Ultra Fractal 4, and Ultra Fractal 3.05 is able to read out-of-range values successfully. (Note: this does not apply to earlier versions. You need to upgrade to version 3.05.)

There is one exception though: due to an oversight, the rotation setting for the opacity part of the gradient should still be in the [-200..199] range to read a parameter set with Ultra Fractal 3.05. Otherwise Ultra Fractal 3.05 will crash.

Workaround

First, try to open the parameter set in Ultra Fractal 3.05. If it crashes, click Continue and click About on the Help menu to verify that you are using version 3.05. If not, upgrade to version 3.05 first and try again.

Otherwise, open the (uncompressed) parameter set in Notepad and search for lines that begin with 'opacity:'. Locate the rotation setting directly afterwards, and add or subtract 400 until it is in the valid [-200..199] range.

  ...
  color=16777197
opacity:
  smooth=no rotation=526 index=71 opacity=135 
  index=98 opacity=211 index=170 opacity=127 
  index=-26 opacity=255
  ...

In the example above, you should change 'rotation=526' to 'rotation=126', subtracting 400. Save the parameter set and try to open it again in Ultra Fractal 3.05.

Note: If you are trying to open a fractal file, or a compressed parameter set, obtain an uncompressed parameter set of that fractal first with a copy of Ultra Fractal 4. You can do this by unchecking the Compress option on the Fractal tab in the Options dialog. See also Parameter files.

Solution