3 ms·

These are all interesting questions. I've been following some of the stuff on Shadertoy, and I think that points the way. Most is 3d, but not all, and in partic

These are all interesting questions. I've been following some of the stuff on Shadertoy, and I think that points the way. Most is 3d, but not all, and in particular there's a lot to be done with distance fields. I've been thinking about blur (and mentioned some approximation techniques), but it's expensive in any context. Maybe if we think in shaders instead of the blur tool, we'll find a visual palette that is both fresh and efficient.

DonHopkins 7y ago
Distance fields are great! What do you think an alternative to PostScript's imaging model (Porter/Duff) formulated in terms of signed distance fields would be like? Much of Photoshop's power comes from representing the selection as first class alpha channels that you can use all of Photoshop's editing and filtering tools on, so you can select something with any of the the selection tools, then take a step back into "quick mask" mode and edit your selection in the "channel" domain, with any of the painting tools or filters, and store selections in extra channels for later use. I wonder how an image editor like Photoshop (and a rendering model in general) could directly and conveniently support signed distance fields as shapes, selections, and channels, as nicely as it supports alpha channels? Back in 1993 (5 years after Photoshop was created in 1988), it sounded revolutionary to use texture mapping as a fundamental drawing primitive, because nobody suspected some day everybody'd be carrying around more computrons than an SGI workstation in their phone. http://www.graficaobscura.com/texmap/index.html http://www.graficaobscura.com/texmap/index.html
- pcwalton 7y ago
  I don't quite know what you mean. I don't think Raph is talking about SDF in the same way that people often talk about it, as a way to use the sampling hardware to improve alpha-tested magnification for fonts and other monochrome shapes. Rather he's talking about computing the distance to a stroke in a shader and using that to approximate a coverage value. You can view that as a type of distance field, and it is, technically, but it's not using the texture mapping hardware as for example the Valve paper does. An image editor that rendered with distance fields in the sense of this article would basically just be a regular vector editor, like Illustrator.
  - DonHopkins 7y ago
    I was thinking that it would be lovely to be able to do the same special effect tricks (outlines, shadows, dialating, glows, bevels, shading, etc) with anything you drew like points, lines, curves, polygons, etc, that (for example) TextMesh Pro can do with text. https://www.youtube.com/watch?v=xfo0NrLJe_k https://www.youtube.com/watch?v=xfo0NrLJe_k
- gardaani 7y ago
  There has been research how to do that with adaptively sampled distance fields [1]. The author (Frisken) also created a 2D drawing tool called Mischief, which is an insanely fast vector graphics software. It's available in the Mac App Store if you want to try it. I think Foundry owns the patents now and they are using the technology in their products. [1] https://www.merl.com/publications/docs/TR2000-15.pdf https://www.merl.com/publications/docs/TR2000-15.pdf

DonHopkins 7y ago

Distance fields are great! What do you think an alternative to PostScript's imaging model (Porter/Duff) formulated in terms of signed distance fields would be like? Much of Photoshop's power comes from representing the selection as first class alpha channels that you can use all of Photoshop's editing and filtering tools on, so you can select something with any of the the selection tools, then take a step back into "quick mask" mode and edit your selection in the "channel" domain, with any of the painting tools or filters, and store selections in extra channels for later use. I wonder how an image editor like Photoshop (and a rendering model in general) could directly and conveniently support signed distance fields as shapes, selections, and channels, as nicely as it supports alpha channels? Back in 1993 (5 years after Photoshop was created in 1988), it sounded revolutionary to use texture mapping as a fundamental drawing primitive, because nobody suspected some day everybody'd be carrying around more computrons than an SGI workstation in their phone. http://www.graficaobscura.com/texmap/index.html http://www.graficaobscura.com/texmap/index.html

pcwalton 7y ago
I don't quite know what you mean. I don't think Raph is talking about SDF in the same way that people often talk about it, as a way to use the sampling hardware to improve alpha-tested magnification for fonts and other monochrome shapes. Rather he's talking about computing the distance to a stroke in a shader and using that to approximate a coverage value. You can view that as a type of distance field, and it is, technically, but it's not using the texture mapping hardware as for example the Valve paper does. An image editor that rendered with distance fields in the sense of this article would basically just be a regular vector editor, like Illustrator.
- DonHopkins 7y ago
  I was thinking that it would be lovely to be able to do the same special effect tricks (outlines, shadows, dialating, glows, bevels, shading, etc) with anything you drew like points, lines, curves, polygons, etc, that (for example) TextMesh Pro can do with text. https://www.youtube.com/watch?v=xfo0NrLJe_k https://www.youtube.com/watch?v=xfo0NrLJe_k
gardaani 7y ago
There has been research how to do that with adaptively sampled distance fields [1]. The author (Frisken) also created a 2D drawing tool called Mischief, which is an insanely fast vector graphics software. It's available in the Mac App Store if you want to try it. I think Foundry owns the patents now and they are using the technology in their products. [1] https://www.merl.com/publications/docs/TR2000-15.pdf https://www.merl.com/publications/docs/TR2000-15.pdf