Just like matrices, you can multiply and divide vectors by scalar values. This is useful when you want to scale the speed of a vehicle up or down, or enlarge a picture. For instance, if you had an object moving… читать далее

As mentioned, the OBJ format is in plain text. If you open it in Notepad or Wordpad, you’ll see lists of vertices and other geometry. Having an ASCII (plain text)-based format rather than a binary one has advantages Table 4.1… читать далее

Evan Pipho F irst off, thanks to my parents for letting me do this; without their support and putting up with not seeing me most of the summer this would have never been possible. A big thanks to Trent Polack… читать далее

The conjugate of a quaternion is used for operations such as rotation of a quaternion by another or rotation of a vector by a quaternion. This is especially useful when you are transforming lighting normals or other operations whereby translation… читать далее

Using the information you have already read, you could try to imple­ment skeletal animation. However, you haven’t learned about how the parent joints actually affect the child joints. Simply using the keyframes would cause every joint to move independently of… читать далее

There are two types of matrix multiplication: matrix times matrix and matrix times scalar. Before you get into multiplying matrices by other matrices, you should perform scalar multiplication because it is much easier. A scalar is simply a number such… читать далее

One of the most important parts of model loading is just getting the file into memory. One of the ways to do this is to use a set of functions from the standard C library, collectively known as the FILE… читать далее

—By 5ean Kent A s you have been reading through this book, you have no doubt heard plenty about the mathematical construct known as a vector. Well, here you are going to be introduced to another kind of vector, a… читать далее

Figure 1.19 Scalar multiplication of vectors. A vector multiplied by a scalar will have the same direction as the original, but a different magnitude (length). Vectors cannot be multiplied together in the traditional sense. Instead of standard multiplication, there are… читать далее

Because the OBJ does not contain any sort of header, you need some sort of resizable array to hold your vertices, faces, and the other com­ponents. In the implementation shown here, everything is loaded into an STL vector, a kind… читать далее