Blender灯光和渲染第六章.doc

UV Mapping and Texturing UV贴图和纹理 Many times, objects contain numerous attributes that define how they look, and theyre not always perfectly uniform in relation to the object. For example, a used paint can would have paint dripping down the sides of the can—if we were creating this can in 3D, wed have to tell Blender that there is a specific spot on our 3D mesh that contains different attributes than the rest of the mesh. This is where UV mapping comes in handy. UV coordinates are, in simple terms, a two-dimensional representation of the texture coordinates of a three-dimensional object. They allow us to tell Blender specific properties about specific areas of our objects in a scene. 许多时候物体包含了许多的属性来定义它们的外观，它们不总是完美的对物体。例如，一个有用的笔刷可以绘制罐头滴落的水滴—如果我们在3D创建这个罐头，我们告诉Blender 3D网格这有一个特别的地方包含和其它地方不一样的属性。这是一个UV贴图。UV坐标是一个三维物体的2D展开贴图的简称。这可以让我们告诉Blender在场景的物体的特定的区域使用特定的属性。 Imagine a bearskin rug for a moment. In order to create that rug, someone had to take the skin and unfold it from its original place on the bears body so that it fit nicely on a floor. This is essentially what we are doing when we create UV maps from our 3D objects. Using special tools in Blender, we can unwrap the UV coordinates so that they lay out flat on a two-dimensional plane, just like our bearskin rug. Imagine a bearskin rug for a moment. In order to create that rug, someone had to take the skin and unfold it from its original place on the bears body so that it fit nicely on a floor.这是必须的为3D图形创建UV贴图，在Blender使用特别的工具，我们可以很好的展开UV坐标到一个平面。 To explore Blenders UV mapping tools, were going to unwrap the wine bottle mesh. This is a perfect example for a few reasons. First, our wine bottle contains numerous material properties—not only will we need to create the overall glass material of the bottle, theres going to be a label running around the bottle as well. In order to position it correctly, we can use custom-made textures and map them to the wine bottles UV set. Sounds confusing? It might, but lets open up ou