Odd question of the day...

[Eric]

Anyone know of a way to vary dab size based on canvas location?  Say you build a preset specifically for waves and you want the brush size to start very small along the horizon, but then you want the dabs to get gradually larger as you as you get closer to the bottom edge of the canvas.  SA 4 can do a lot of things I've never really thought of, so I thought I'd ask about this. 

I could think of various other canvas position based effects that would be fun to play with as well (gradual color changes for example),  that's just a practical manual painter type circumstance that popped into my mind :)

[Eric]

other than manually of course... lol

[liveart]

Horizon foreground background is a visual analysis that I have been asking John  to add. I agree it you be very nice to have. So far it is not there yet.

Still there is a way to get the result that you want. Though not as directly as it could be.. [John can you add vertical location and inv vert location to the brush size modulators please]...

Eric.. back to your query,

Look under path size modulation and you will see one for vertical location (john inv vertical would be a good add)

If you set the path length to vary by vertical location the program will generate shorter paths a the top and longer ones as it moves toward the bottom of the canvas.

look under the brush modulators and you will find a mod for path lenth. Setting the mod to path length with the path length being modified by vert location will indeed give you a smaller nib near the top of the canvas and a larger one near the bottom.

so you are half way home, now how to get this size modulation to start at the horizon... use the rectangle selection option and select the area that bound by the horizon at the top and the bottom of the canvas at the bottom.

run your modified preset with the mask on.

voila

[Eric]

Why not horizontal and radial as well, possibly radiating out from a chosen starting location?  Not just edge to edge...  I suppose the starting point of the first stroke on the canvas could be saved and used as the starting canvas location when in that mode... or maybe on a per layer basis, so that way you could build things up with multiple layers with different starting points. May as well think big, as you told me before... lol

[liveart]

just something to think about. path length and brush size are of course adjustable, and when you are thinking in terms of hand painting or coming from a standard painting program it is natural that one would think of mods to these parameters to get a variable brush size look.

However, SA is not a basic painting program. Because of the way SA stacks paint strokes the apparent size of the stroke in the final image may be related to something completely different from the brush size.  Long paths that overlap each other for example will result in what appears to be shorter strokes. The same can happen with large brush nibs, while the inverse can happen with smaller ones. They can combine to make what might appear to be a single large stroke in the image.

Background or stroke texture in particular can build up to create a completely different look from what one might expect looking at a single stroke

So in addition to brush size you will want to play with stroke placement and quantity.

...

Have fun.

[Eric]

I realize that, but I was more or less thinking of using SA as a manual paint application... which is perfectly possible.  So far I've mostly been experimenting, and asking questions.  I've found the auto functions of SA4 great for the purposes of breaking images down into abstracts so that I can look at them in new ways. Helps give me ideas.

When it comes right down to it though.  I'm painting because I enjoy it, So I usually like painting my pieces manually, which is also possible in SA despite its bent on simulating artists' results.  As far as single dab overlapping issues... that would depend on the how big the steps in brush sizing you wanted to use were although I imagine it would be best to start painting where you want bigger dabs... working your way to the smallest... that way you're not just completely hiding smaller dabs with ones that have gotten too large...

There's also nothing that says that every option has to work with every single other option... if one option makes another incompatible...the incompatible option just gets grayed out... then again there are plenty of people out there that do like creating unusual art and they might want to do something like that with larger strokes.  Who knows.

[John Dalton Synthetik Software]

Size modulation currently has border proximity (and inverse) as size modulators.

If you want to do vertical or some other spatially modulated option, you can do it by using the Bus1 modulator in conjunction with another hidden layer. Bus modulation lets you use the luminance of another layer as a spatially variant modulator. You set the layer being routed to the Bus in the Miscellaneous control panel.

For a vertical size modulation, you would put a vertical luminance gradient in the hidden layer you are routing via Bus modulation to use for size modulation..

[Eric]

Thanks for telling me a way to do it :)