directional light

[jammer64]

Use a wide FOV spotlight with a large radius placed very far away from your scene. make the near-clip plane relatively close to your FOV but not so much that it clips off some of your scene. The farther away you place this spotlight the more it will seem like there is no single source point of light. That's about as close to the type of light you're speaking of as you can get :S

believe me, i've already tried with such technique as i had described earlier but the light being placed far it produces artifacts (giant black triangle) and shadows turn into unreadable squares thus this is no option unfortunately. i have some experience in mapping using unreal engine thus lights are not a secret for me