- From: Tavmjong Bah <tavmjong@free.fr>
- Date: Fri, 03 Feb 2012 13:27:15 +0100
- To: Israel Eisenberg <owlgems@yahoo.com>
- Cc: Jasper van de Gronde <th.v.d.gronde@hccnet.nl>, Cyril Concolato <Cyril.Concolato@cisra.canon.com.au>, www-svg <www-svg@w3.org>
Hi Israel, Thanks for sharing your interesting results! I've been studying your email and your figures. I've got a few comments and questions. I don't have either Illustrator or Corel Draw. * To edit a patch one seems to need two sets of control points. One set to control the geometric shape of the patch and one set to control the color spread. How does Illustrator handle this? * Having a derivative of zero along the edge handles the case where the color at the edge is at a maximum or minimum but we also need to smoothly join patches where the color along the edge is in between. (And the problem is more complicated when red, blue, and green all have different profiles.) * How did you generate the right side image for bilinear_combos_compare.html? If one stares at it long enough, one can see a grid structure, each quadrant being divided into an 8x8 grid. I am guessing that corresponds to a simple bi-linear mesh that Illustrator uses for export. They must use such a mesh for PostScript and PDF export as that is all that those standards allow. Further evidence of this is your finding that the basic patch profile is broken into linear sections at the top. In fact, looking at final_profiles.html it looks like the horizontal profile is broken into eight linear sections. * I am rethinking our decision to use type 6 rather than type 7 meshes. See: http://tavmjong.free.fr/blog/?p=361 * I am open to making SVG meshes use something like an interpolant provided that: 1. It doesn't complicate the syntax. 2. There is a straight forward way of editing such meshes. 3. There is a simple way to export them to PostScript/PDF. Tav
Received on Friday, 3 February 2012 12:27:50 UTC