>>434 OpenGL, the most popular graphics library in the world, requires that z value in homogeneous clipping space be within the range between -w and w, as is the case with your platform. Historically, I believe, this type of projection matrices rather than DirectX-style projection matrices (0 < z < w) has been widly used.
>>437 You can use the upper-left 3x3 matrix of your transform matrix (from world space to object space) to transform a direction vector into object space if and only if the 3x3 matrix is orthonormal, which means the 3x3 matrix represents pure rotation without any scaling or shearing. Otherwise (if the 3x3 matrix is not orthonormal), you need to use the inverse transpose of the upper-left 3x3 matrix instead.
>>438 I agree. No Japanese translation is needed for us. 327, we hope you meet our request. Thanks in advance.
