Tutorial 4 - color and blending

Until now all of our Geos have been white, so now is the time to add a little color! In addition to demonstrating color, this tutorial will cover how to enable alpha blending for transparency.

The 'Geo_color' patcher contains a little render chain with the color object. The color object takes four arguments for Red, Green, Blue, and Alpha, and these values range from 0 to 1 in floating point (numbers outside this range are clipped). The color object additively mixes the Red, Green and Blue channels to display all of the colors available on the computer.

Open the 'transparency' subpatch to see how to make an object transparent. The alpha object enables alpha blending and the fourth argument to the color object controls the level. Set the Red, Green and Blue to a nice color and then move the alpha level from 0 to 1, and watch the object 'fade out'.

The third subpatch has two render chains to demonstrate how to blend between two Geos. Think of it like a Geo cross-fader. Here it is important to notice that the right render chain is 'on top' of the left one. This becomes important when building larger and more complex chains. Move the HSlider above the xfade abstraction to see the transition between the red square on the left and the blue one on the right. Change the size of each square too.