Quick and Easy rivers in Inkscape with Fractalize and Tweak

This tutorial assumes basic familiarity with Inkscape including the Bezier and Edit Paths tools.

First, Ctrl+Shift+D to bring up the Document Properties. Select "Snap", and make sure Nodes are snapping to Nodes.

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Now select the Bezier Tool and draw the rough path of your river as a sequence of straight segments roughly the same length.

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Next add major tributaries the same way. Start at the corners of existing paths. The line will snap to the corner automatically.

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Select the paths and choose Effects → Modify Path → Fractalize. Turn on Live Preview, set subdivisions to 1, and pick a smoothness that look good. Apply when you are done.

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Use the bezier tool to add lesser tributaries using the new segment length. Make adjustments to the paths with the Edit Paths tool as you see fit.

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Fratalize and edit as many times as you feel you need. When you have enough branches, you can apply more fractalizing at once by increasing the "Subdivisions" parameter.

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Next select all the paths and Stroke to Path (Ctrl+Alt+C) and then with them still selected, choose the Tweak tool (Shift+F2) and start playing wit the rivers. Use the Grow mode to widen a stretch of river, Shrink to narrow it, and Push to shift it sideways. You'll have to adjust your Force, Size, and the zoom level to get the right effect and it might require some practice. Some of the tributaries might become detached in the process, but this can be fixed later.


You should end up with curvy, rivers with varying width. Some of the tributaries may get detached in the process but this is easy to fix.

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To fix any detached tributaries, use the Edit Paths tool to drag the loose nodes into place. You can also make other fine adjustments to the paths if you feel it necessary.

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Congratulations, you now have a river system.

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To accomplish this task in Adobe Illustrator, use Effect > Distort & Transform > Roughen. Set the Points to "Smooth" and adjust the Size and Detail downward.

Convert the stroke to outlines with Object > Path > Outline Stroke, then use the Bloat and Pucker tools (hidden under the Warp tool) to adjust the stroke width. To adjust the properties of the tools, select the tool, then double-click on its icon in the toolbar. Or you can hold down alt to interactively change the brush size prior to using it.

I was just about to ask if there were any fractal functions for illustrator or photoshop. Roughen is the closest I've found, but I was hoping for more.