The clouds in Minecraft are semi-transparent and are rendered on both sides. If you fly into the cloud you can see inside of the cloud. If I render clouds the inside faces would be visible on the outside. How can I prevent that? Z-Ordering the faces and render near to far with depth test on? There must be a better, easier way. Could the accum or stencil buffers be used somehow?
UPDATE : I think the crucial point everyone is forgetting is that these clouds and semi-transparent and "blended" into the scene as each face is rendered. If two faces are rendered on top of each other the "white" texture will double up which is undesired. The faces also seem to have slight lighting variations which would rule out using a stencil.
UPDATE2: Just another note. Each cloud is 12x12x4 blocks (roughly). Larger clouds are just a group of the base clouds stuck together.