Both God Of War: Chains Of Olympus and God Of War: Ghost Of Sparta will be playable in high-definition on the PlayStation 3 as part of next month's God Of War Origins Collection (God Of War Collection: Volume II in Europe).

But getting both games running on PS3 hasn't been a walk in the park for original developer Ready At Dawn: "The first goal we had was simply the daunting task of up-rezing the engine and content authored on a PSP running at 480 x 272 resolution and 30 frames per second to 1920 x 1080p at a steady 60 fps on the PS3," art director Nathan Phail-Liff explained.

"This required a custom PS3 version of our engine, coded in-house exclusively for Collection II, as well as a painstaking process by art team. We ended up going through every single character in the game and doubling or tripling polygon count by hand, as well as up-rezing and re-painting every texture across both games at 4x resolution on both characters and environments."

Despite the challenges of upscaling the PSP titles, Ready At Dawn then decided to include 3D functionality into the games. "The quality of the final result [...] surprised us [so much] that it actually sold myself and a number of others on the team 3D TVs in general. Personally I wouldnÂ’t want to play the games any other way after being able to experience it firsthand."

With the game looking so good in high-definition (and 3D), Ready At Dawn faced another problem in the form of the game's cut-scenes.

"Between Chains of Olympus and Ghost of Sparta we had over an hour of pre-rendered cinematics, and the gap in video resolution between our PSP source footage and full HD was so extreme that no matter how many custom video up-scale solutions we tried, there was just a glaring quality difference between the 1080P real-time gameplay and the video," Nathan explained.

"It was pretty demoralizing for us to play the game in beautiful HD and hit a cinematic trigger where Kratos looked like he was rendered through a dirty sock, so we realized we would just have to bite the bullet and properly re-render all cinematics in full 1080p. To do this we ported all of our cinematic scenes to the PS3 and, months and terabytes of data later, had every single frame re-rendered in HD through the new CollectionÂ’s engine. From there we had to up-rez all of the post production effects and re-composite every single cinematic again in HD, giving us a final result that blended seamlessly with the in-game quality."

Phew. There's a demonstration of the game running on PlayStation 3 side-by-side with the PSP version after the jump. Needless to say the hard-work put in by Ready At Dawn was worthwhile.

God Of War: Ghost Of Sparta is possibly our favourite God Of War title to date, so we're looking forward to replaying the re-mastered version.