Paint brush in Mask

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Robert Schleif
Posts: 340
Joined: May 1st, 2009, 8:28 pm

Paint brush in Mask

Post by Robert Schleif »

For me, the effectiveness of the paintbrush in masking operations could be substantially improved with the following adjustments. Although the representation of the paint brush's softness in the mask window shows a nice gradation of strength, when I paint, the brush seems to be much less soft, with the gradation occurring only in the final fifth of the distance from the center to the edge of the circle representing the brush's extent. It would be nice if the maximum radius were several times larger than the 1,000 pixels currently possible as my standard images are larger than 8,000 x 5000. I seem to use the transparency at either 0% or 85-100%. Expanding the region from 85 to 100 would be helpful.
jsachs
Posts: 4203
Joined: January 22nd, 2009, 11:03 pm

Re: Paint brush in Mask

Post by jsachs »

For painting a large area smoothly with a semitransparent mask, I recommend using the freehand outline tool followed by the mask blur tool -- this applies the mask much more evenly and with a consistent falloff around the edges. The effect is similar to dodging and burning in the darkroom but with much more control.

The paint tool and mask paint tool work by repeatedly applying the brush shape as you drag, with the overlap between applications controlled by the Spacing setting. For small spacing values, there is a lot of overlap and this makes the brush effectively less soft and more opaque compared to what you get with a single click. For large spacing values, there is less overlap, but the result is rough. These effects are more visible when you use a very large radius.

This suggests a more sophisticated version of the painting tools could be created by fitting a curve to the brush track and when you finish dragging, filling in the path by setting the mask value at any given point to a function of the distance to the closest point on the curve. With no Spacing parameter, the softness and transparency settings would be more consistent and the result would be perfectly smooth. Even so, the freehand outline followed by blur method would still remain a better way to draw a smooth mask over a large area as you would not need to fill it in with overlapping strokes.
Jonathan Sachs
Digital Light & Color
Robert Schleif
Posts: 340
Joined: May 1st, 2009, 8:28 pm

Re: Paint brush in Mask

Post by Robert Schleif »

That sounds like a good suggestion, thank you. I don't recall seeing it in the documentation.
jsachs
Posts: 4203
Joined: January 22nd, 2009, 11:03 pm

Re: Paint brush in Mask

Post by jsachs »

The Picture Window Tutorial has an extended example of the freehand outline/blur technique. The big advantage of this method is that you can vary the softness and see the results before finalizing the mask.
Jonathan Sachs
Digital Light & Color
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