Vein growth guide

Start

The tool opens with two sample pictures, A and B, and the Leaf veins preset. The picture fills the frame; the panel sits beside it.

A current browser with WebGL. Chrome, Edge, Firefox and Safari all have it.
Two pictures of your own, if you want them. Any image the browser can open works; the samples are there until you swap them.

Open Vein growth and tap the picture. Veins grow out from that point, and picture B shows through under them until it fills the frame. See tap origin.
Tap again. This time the veins carry picture B back into picture A.
Press a preset under Presets, such as Gold circuit, then press Replay at the top of the panel.
Change Sprout from to choose where the veins start: the point you tap, the border or the bottom edge.
At the top of the panel, press the Image A and Image B tiles to pick your own two pictures, or drop two at once.
Press Save PNG for a still, or Record video to keep one full run.

With Sprout from on Tap point, each tap grows a new network from that point, so the run starts a moment after you tap. Replay keeps the network you have.
A tap during a run does nothing; wait for the veins to finish. Replay always starts again at once.
Between runs the frame shows only the first few veins at the start point, so press Replay to see what a slider does.
Moving any slider takes the highlight off the preset, and the next run uses your settings.
The frame takes the shape of picture A. Picture B is stretched to that shape, so two pictures of the same shape look best.
On a phone the controls sit in a bar at the bottom of the screen. Tap the bar to open them.