Detecting gaps in Live Paint groups

show more Detecting gaps in Live Paint groups provides you with in-depth training on Design. Taught by Mordy Golding as part of the Illustrator CS4 Beyond the Basics show less
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Detecting gaps in Live Paint groups

So we know that the Live Paint feature inside of Illustrator allows us to apply fill attributes to areas that look as if they are enclosed. Additionally, we also know that Illustrator was probably no fun as young child because it always colors in perfectly insides the lines. Well, one of the great things about Live Paint is that there is some bit of leeway that's involved. In other words, there is room for error. Let me show you exactly what I mean here. I'm going to start by drawing four lines again that intersect each other. I'm going to take these four lines, select them and then turn them into a Live Paint group. I'll choose Object > Live Paint > Make.

So I now have the ability to use a Live Paint Bucket tool to simply select the yellow color and fill that middle area there with yellow. I also know that these paths are still individual paths. So I can use my Direct Selection tool to simply go ahead and just select one of them and change our edit to paths themselves and the filled area just updates accordingly. But let me zoom in on this piece of artwork a little bit and let's focus on something else here inside of this Live Paint group. Notice that as I move one of these paths around, the fill updates and that's because the area still appears if it's closed.

But what would happen if I take my path here and I would actually create it or edit it so that now the area is no longer enclosed. What happens to that yellow fill? The answer is that the yellow fill completely disappears. Because they no longer have an area that looks like it's closed, that yellow paint has nowhere to go. Now if I were to go ahead and close that area again, once the yellow paint leaves that particular area, it doesn't come back again. Of course, I could simply the Live Paint Bucket tool and apply that yellow color once again. But let's do a different type of edit here. I am going to take that same path over here. I'm actually going to adjust this so that there is just a small little gap that's there. Take a look at this. If I zoom it really closer, you can see that I now have a gap that appears between the paths themselves, yet the yellow color is still here. Now how is that happening? Even in a program like Adobe Photoshop, for example, where I do have a Paint Bucket tool that I could flood fill an area, we know that if there is even a small gap, even one pixel, that yellow would now fill the entire document. But somehow inside of Illustrator, even though there is a gap there, the yellow fill is still being applied to that area.

So if you go back to the rule of Live Paint from in here where we say that, you can fill in the area that looks like it's enclosed. Here I have an area that looks like it's open or you can say that it looks like it's almost closed. And yet, I'm able to apply a fill to that region as well. This happens because there is a certain behavior that's built into the Live Paint feature. Something called Gap Detection. In fact, let me zoom out just a little bit over here. I'll select my Live Paint group that I have right here and I'll go to the Object menu and I'll choose Live Paint > Gap Options. A dialog box opens up, basically allowing me to see how I can treat this particular Live Paint group with regard to gaps.

Now, by default, when you work with Live Paint groups, the Gap Detection option is turned on. Just to show you, by the way, I can simply uncheck this option with the Preview option turned on. You could see that now the yellow paint disappeared. That's because there is a gap that's right here. But by turning Gap Detection on, the yellow fill stays intact, even though there is a small gap there. Now, what determines a gap? Well, you can actually choose to have paint stop at small, medium or large gaps or alternatively, you can choose Custom and specify your own value. This behavior inside of Live Paint, Gap Detection is a game changer.

As we've already seen, Live Paint allows you to apply fill attributes not to distinct vector objects but to just areas that look like they're enclosed inside of Illustrator. Now we see that those areas don't even need to be closed at all. In fact, what this really does is it allows me to think about Illustrator in a non-perfect way. Here, I can fill areas that are not perfectly closed. You can almost say that the Live Paint feature with this Gap Detection flies in the face of the very core of what vector graphics are. But in really what this feature does is that it allows you to draw in a far more intuitive fashion inside of Illustrator.

Now as with anything there are always pros and cons, but if you think about it, many times when you're drawing inside of Illustrator and you want to be able to paint certain areas, you may find it far more useful to create Live Paint groups rather than try to struggle using the Pen tool and then chop pieces apart using Pathfinder. More importantly, when you're trying to create artwork that may look a little bit less than perfect, working with Live Paint and Gap Detection can get you great results in a very short amount of time.

Detecting gaps in Live Paint groups
Video duration: 4m 17s 9h 42m Intermediate


Detecting gaps in Live Paint groups provides you with in-depth training on Design. Taught by Mordy Golding as part of the Illustrator CS4 Beyond the Basics

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