This sample illustrates the use of the glColorMask() to inVega Prime to selectively render to only certain color bands of the fr a me buffer. This sample defines the class myApp, which is derived from vpApp, and overrides the vpApp::onKeyInput() method to allow for the keyboard input listed below. The sample uses pre / post draw channel subscribers to set the color mask so that the channel can be rendered as monochrome green. -This sample illustrates the use of the glColorMask () to inVega Prime to selectively render to only certain color bands of the fr a me buffer. This sample defines the class myApp, which is derived from vpApp, and overrides the vpApp:: onKeyInput () method to allow for the keyboard input listed below. The sample uses pre/post draw channel subscribers to set the color mask so that the channel can be rendered as monochrome green.