Ray J – Dance Off ... With Tupac Hologram (VIDEO)

Ray J celebrated what would have been Tupac’s 44th birthday by getting down with the late rapper's hologram, the same one unveiled a few years back at Coachella.

Ray went to the Hologram USA showroom in Bev Hills and danced with the famous lifelike image.

The good folks at Hologram USA tell us anyone can hang with the Tupac hologram ... for free.

Not free? The parking ticket Ray J got out front because apparently time flies when you're dancing with Pac.