On Mon, 2004-03-22 at 18:20, bulia byak wrote:
When these things are done, I will be almost happy. It will be relatively easy then to emulate most meshes, fields, etc. by overlaying semitransparent elliptic gradients.
How does that follow? Nobody has shown how to transform a gradient mesh into a gradient field (a very good name actually).
I'm not a mathematician; I'm a designer. I think I can approximate well enough (for design purposes) most useful meshes using ellipses, and a still better approximation is possible with blurred strokes of blur filter on shapes.
Well, with a little skill it's possible to get pretty much any effect you want manually with a combination of linear and radial gradients.
I've spent some time poring over the Postscript Red Book (level three), and there are actually a whole bunch of different types of gradient meshes that Illustrator may use.
Many of them cannot be efficiently approximated using only a combination of linear and radial gradients, at least not automatically (and I think there are some less artistically important corner cases that are completely unpractical).
I think we're best off providing UI to utilize the features we do have from SVG; essentially what I'm thinking would be "composite fills".
Basically, the idea would be that you could take an existing fill and layer another fill on top of it, so e.g. you could very easily build up a complex gradient fill with layered radial gradients. But you could also throw other fill types in the mix as well.
I think it'd be relatively easy to implement -- any non-trivial fills could be implemented behind-the-scenes as SVG <pattern>s with a stack of filled <rect>s for the fill "layers".
-mental