Hollywood forums

In HollyPaint I've actually string gadgets for the parameters for BarrelDistortBrush, but I'd prefer sliders. I wonder what range of values would be useful. Other question: is the simple form with 4 coefficients good enough for every day use or should I implement the variant with 8 coefficients?

The variant with 8 coefficients is only necessary if you'd like to have fine-tuned control over both axes, otherwise the simple version will be enough. Using sliders instead of string gadgets will be more complicated as you'd have to implement your own stringify hook because you need floating point values for the coefficients and they can also be negative. Not sure if sliders would be very intuitive here. Concerning the range of values it is of course dependent on what distortions you'd like.... for most cases I can think of ranges of -2.0 to 2.0 should be sufficient, though.

Ok, to simplify it a bit I'll use a range from -20 to 20 and translate that to -2.0 to +2.0.