2D "slider" in parameters panel

[jasonrohrer]

It would be nice to explore two related parameters with one mouse drag. For example, there might be and x and a y parameter. Currently, we have to click the X slider, move it, and then later drag the Y slider. This makes exploring the whole parameter space much more tedious.

The solution is a little 2D rectangle with a slider handle in it that can be moved in 2 dimensions.

I haven't tried it yet, but I'm assuming that a color picker, along with some scaling, could be used as a "hack" to get this functionality in the current software.

There also might be an opportunity for innovation here for a 3D slider. One idea is to let mouse position control A and B, and let the scroll wheel control C. So by dragging the mouse around while scrolling the wheel, the entire 3D parameter space could be explored. The third parameter could be represented visually with the color of the slider handle (from black to white), or maybe by a little clock hand on the slider handle that rotates.

[doug-moen]

Sounds like a good idea. Contributions are welcome.

[lf94]

ocornut/imgui#3484