This tutorial will show you how to create custom textures for use in creating maps for the Source engine. The process is also the same for creating textures for models, sprays, mods and essentially any image data within any Source game.
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Make Your Source Maps Glow with Cubemaps and HDR
Is your map looking a little bit flat? Does it need that extra zing? Then High Dynamic Range can help you add that warm glow to your creation.
HDR is a subtle effect; a simple explanation is that is the effect of your eyes adjusting to a dark room after being in the bright outside. This means that darker areas will be darker initially, and will then rise to a brightness level more suited for interior gameplay. This dynamic balance of brightness adds contrast to your map, meaning an overall brighter and vibrant experience.