Initialize or Tools
Update from the lower-right quadrant of the quad menu.
Only one ActiveShade window can be active at a time.
If you select an object before you invoke ActiveShade, ActiveShade is done only for that object. This can greatly increase the speed of ActiveShade.
Similarly, once the ActiveShade window is open, the initialize and update steps (whether automatic or manual) are done only for the selected object.
For the sake of interactivity, the ActiveShade window is limited in what it can update. An ActiveShade rendering is typically less precise than a final production rendering.
Initialize from the quad menu (lower-right quadrant). This updates the ActiveShade rendering.
If you see this happening, right-click the ActiveShade window and choose Tools
Initialize from the quad menu (lower-right quadrant).