Let There be Clouds! Fast, Realistic Cloud-Rendering in Microsoft Flight Simulator 2004: A Century of Flight

Niniane Wang (Microsoft) Available Online at Gamasutra, 2004, Game Developer Magazine (Jan 2004)

Abstract: This article describes how clouds (altocumulus, stratus, and cumulonimbus, and cloud coverages ranging from a few sparse clouds to a dense, overcast sky) were rendered in Microsoft Flight Simulator 2004. Each cloud was modeled as five to 400 alpha-blended textured sprites. The sprites face the camera during rendering and together comprise a three-dimensional volume. With the help of a custom plug-in for 3DS Max, artists were able to highly customize clouds. The article describes the plug-in and provides details on in-game rendering.

Cube Map Lighting Techniques

Kenneth L. Hurley Game Programming Gems 3, 2003.

Abstract: This article will describe some ways to encode different lighting conditions as well as other properties within cube maps. It will give a brief overview of the properties of cube maps and how to index into them. Topics include: Physical Properties of Cube Maps, Getting data to/from a Cube Map, Rendering with the Cube Map, Encoding Cloud Cover, Encoding Lights in a Cube Map, Encoding Diffuse Lighting in a Cube Map, and Encoding a Day/Night Cycle into a Cube Map.

Generating Procedural Clouds Using 3D Hardware

Kim Pallister (Intel) Game Programming Gems 2, 2001.

Abstract: In this article, we'll set out to procedurally generate cloud textures that possess some of the properties that real clouds exhibit. In additon, because textures typically reside in graphics subsystem memory, we'll aim to generate the procedural clouds almost entirely using the graphics hardware. Finally, we'll address some ways to scale the technique's quality and performance requirements in order to accommodate a range of target machines.

Volumetric Rendering in Realtime

Dan Baker and Charles Boyd (Microsoft) Available Online at Gamasutra, 2001.

Abstract: Most current implementations of fog in games use layered alpha images. This technique, however, does not bare significantly resemblance to how fog actually composites in real life, since density of the fog from the viewer is not modeled in any way. In order to create fog effects in a game, it is first necessary to create an analytical model that bears some resemblance to the mechanics of real fog. Includes a pixel shader supplement.