UV coordinates are layed out visually and exported as a square bitmap image with a resolution anywhere from 512 x 512 all the way up to 6000 pixels by 6000. Unwrapping: Unwrapping is the process of assigning each polygonal face a set of UV coordinates on the two-dimensional image plane. Unwrapping a model is very similar, except there are usually more than six faces to flatten. If that paper cube were a 3D model, every fold would be an edge, every corner would be a vertex, and every flat area would be a face. Have you ever made a cube out of paper? If so, think about the shape you needed to cut into the paper in order for it to properly fold into a cube-it probably looked like a cross, four units (faces) high and three across. An easy way to visualize what a UV layout looks like is this: ![]() In this way, all areas within the boundary of the UV layout correspond to a specific spot on the model. Each point on the two-dimensional plane is called a UV and represents a vertex on the 3D object. However, in order to apply a texture map to the surface of a model, it first needs to be unwrapped and given a functional UV layout for texture artists to work with.Ī UV layout is a visual representation of a 3D model flattened onto a two dimensional plane. To put things in very general terms, texture mapping is the process of adding color (or other information) to a 3D model by projecting a two-dimensional image onto its surface. Texture mapping, invented by Ed Catmull in 1974, is one of the more ingenious breakthroughs in the history of computer graphics. Unwrapping a Model and Creating a UV Layout In part-two we'll return with an explanation of texture-mapping, and then we'll round out the series with a quick look at shader networks. In this first section, we'll discuss UV layouts, and everything that goes along with creating them. Shading and texturing may be two sides of the same coin, but they're still fundamentally different processes, each deserving its own discussion. Without a good team of texture painters and shader writers any CG production will ultimately look flat and unconvincing. Or Wall-E without his fantastically weathered-and-worn paint job. Try to imagine Rango without his colorful, scaly skin. The job of a texturing or shader specialist may sound somewhat less glamorous than than that of a modeler or animator, but they're equally instrumental in the process of bringing a 3D film or game to fruition. ![]() Surfacing, which includes UV Layouts, texture mapping, and shader building, is the overall process of adding detail to the surface of a 3D object. Obviously, this isn't the way the model ultimately appears in the final render, so how is it that a model goes from an uninteresting shade of gray to the fully detailed characters and environments we see in movies and games? By default, a recently finished 3D model is a lot like a blank canvas-most software packages will display it as an evenly lit, neutral shade of gray.
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