In the opening that was re-rendered by Double Negative for IMAX 3-D, Diagon Alley is attacked by the Death Eaters. All Images: © 2009 Warner Bros. Ent. Inc.

View clips and trailers of Harry Potter and the Half-Blood Prince at "Harry Potter Haven" on AWNtv!

Like most franchises these days, Harry Potter has become more and more naturalistic in its vfx. That was the mandate of director David Yates, who returns for his second outing with The Half-Blood Prince. There's no denying the influence of Chris Nolan's grittier take on Batman. As Harry (Daniel Radcliffe) rapidly matures into manhood under Professor Dumbledore's (Michael Gambon) wise tutelage, and the Death Eaters wreak havoc on both the Muggle and Wizard worlds, there is a wonderful sense of foreboding that permeates the movie. After all, this is the transitional story as Harry and his pals prepare for their final confrontation with the Dark Lord in The Deathly Hallows, which has been split into two movies for 2010 and 2011.

And it's paid off for Warner Bros. at the box office, where Half-Blood Prince has broken the record for the biggest five-day gross in history, making $158 million.

Overseeing the vfx once again is Tim Burke, who relied on Double Negative, MPC, ILM, Rising Sun and Cinesite to provide most of the work, which has gotten a lot more sophisticated and complex in keeping with the escalating jeopardy.

"David treats Half-Blood Prince very much as a drama piece," Burke explains. "The way we worked the team was not to get bogged down in visual effects set pieces. And a lot of the work throughout the film is invisible: a lot of environments and set extensions and all of the bluescreen work that we hope people won’t spot that add to the storytelling. As much as possible, we allowed him to shoot things freely and pretty much work with the actors and worked around him. There are only a couple of really big set pieces. A couple of visual effects-led title sequences with CG environments and we relied on previs. But we let the drama unfold."

And the franchise has taken particular advantage of the latest advancements in HDRI, facial capture and fire and water simulation. "It's been interesting seeing the companies improve that have worked from the very beginning," Burke continues. "I think the environments are an important thing that we're doing more and more of, and, as the tools they develop get more sophisticated and photorealistic, that's pretty much the key. We feel confident that we can shoot on partial sets or complete greenscreen stages, knowing that we can make a photorealistic environment for the actors to be in later on. On these films, like a lot of franchises, there's a lot less traveling to locations now and more work being done back here at the studio. I think we had something like 15 sets built on the backlot at some time or another, of which have partial or total bluescreens.

Yates wanted special attention paid to the crossover from the Wizard world to the Muggle world to emphasize the death and destruction at stake, with Double Negative rebuilding a large portion of London's West End in CG. As an added bonus, the opening and closing will appear in IMAX 3-D beginning July 29.