KnobMan Online Help
Preview pane shows the result of rendering. three modes (Preview/Render/Test) are available. the number of frames for preview or render are set in preference page. The 'File'-'ExportImage' command will use the frames for 'Render' irrespective to preview mode.
'Test' mode shows the result of animation by dragging the slider
Dragging the preview image
Dragging from the Preview pane will make the floating image of the knob that can be moved to outside of window. This will make easy to confirm how looks the knob on background image. To hide the floating image, click right button.