For an episode of MGM’s Stargate series called ‘Tok’ra,’ Vancouver’s Lost Boys Studios was charged with the creation of the transporter rings through which the show’s stars travel.

But, as the Lost Boys team says, ‘You see one ring transport you’ve seen them all,’ so this time an additional challenge was thrown in – make the rings interact heavily with their environment; specifically, make five transport rings appear to be pushing up through a sea of sand.

The scene also features actors running in front of and behind the rings, with sand and energy flying all the while.

The production team created a practical effect of the sand exploding forth, ‘kind of poufing up in a ring and then dissipating,’ says Lost Boys effects supervisor Gary Walker.

A plate was also shot with the actors.

They then applied extensive post manipulation to match the rings to their environment, with color corrections for contrast and to lend a deeper, churning appearance – all duplicated five times and the five rings themselves computer generated.

The Lost Boys did paint reveals of the rings through the sand and through the dirt explosions; another practical effect added the top level of sand being pushed up and flung into the air, with post manipulation again to make it fit with the CG components.

The final sequence shows the rings disappearing, complemented by energy fields which signal their departure. The Lost Boys painted some particle elements for the energy fields and composited them in to make the rings disappear with a flourish.

The gear: The rings were animated and textured using Alias|Wavefront PowerAnimator and compositing was done with Discreet Logic Inferno.

The artists: Walker was Lost Boys’ vfx supervisor, Elaine Sipos animated the rings and Judy Shane was compositing artist. John Gajdecki and Simon Lacey were the visual effects supervisors.