Generate Mesh Using Boolean Modifier Over Time I want to create a mesh that is the "union" of an object at it's various locations in the timeline. 

For more clarification, here is a simple example. If I were to start with a UV Sphere, and animate it to move right 5 units...then apply this modifier that I'm looking for, I would expect the resultant mesh to be a "capsule" (long pill shape) that is 5 units long...because it is the union of the UV Sphere at all it's locations in time.







Is there any way to do this in Vanilla Blender? If not can someone point me in the direction of a plug-in that would allow for this? The end goal is to use this on a rigid body simulation to generate a mesh.
Array with end caps

Example using default cylinder and UV sphere. (matching loop vert count)

Add a UV sphere in edit mode select half and P separate by selection.



Add the default cylinder with no ends (None) Add an array modifier.  Use the two sphere halves as end caps.  Make the relative offset in z (arbitrary, chosen since it is  default alignment)



We now have our capsule shape... but not the ball.

Add a shapekey to the cylinder, and make this zero scale in Z. SZ0  Now whenever the influence of this shapekey is 1, the whole thing will be a ball, no matter what the count is on the array modifier.



Put together quickly from default primitives as a proof of concept.  Once the shapekey is &lt; 1 the length of trail can be adjusted using array modifier, as well as shapekey, depends on the curliness of the path.



Re making a motion trail

Could script this to make a motion path based on the transform of the object.. Could be tricky re handling bounces etc.