If you've run SolidWorks since version 2008, you've undoubtly run into Instant 3D since it's toggled on by default right out of the box. (Unless you have a savvy Admin who's setup your installs to have it off.)
The purpose of this blog article is to explain as simply as possible, the what, where, & how's.
WHAT is Instant 3D? It is an optional(toggles on/off) interface for changing sketch and feature values dynamically by dragging. If you're in need of making the fasted what if changes to a model, it's the hot ticket.
HOW to Use Instant 3D? It
With Instant 3D Off:
--One double clicks a face to see dimensions, double clicks a dimension to see the modify box. (Simple, standard stuff from way, way, back.)
With Instant 3D On: (SolidWorks Default) It's a bit more complex.
--One single or double clicks a face to see dimensions.
--Drag those blue dots! Heck yea!
----Keep your cursor on the ruler to snap to the ruler increments.
----Keep your cursor off the ruler to get values inbetween the ruler increments.
--If one double clicks a dimension, they see the modify box.
--If one single clicks a dimension, they see only a small box to change the value.
It gets more confusing with configurations: (w/Instant 3D On)
--The modify box provides an icon to determine if the dimension is All, Specified or This configuration.
--The small box doesn't provide any icon or clue if the dimension is All, Specified or This configuration.
--Dragging the Blue Dots, doesn't provide any icon or clue if the dimension is All, Specified or This configuration.
--It all boils down to how is the dimension across the configurations right now?
----If the dimension is common to All Configurations, changing the value by dragging or small box affects ALL CONFIGURATIONS.
---If the dimension is This Configuration or Specified Configurations changing the value by dragging or small box affects just THIS CONFIGURATION.