هل هذا منظور صحيحة مصفوفة فوف؟

Question

لدي منظور FOV، ولكن عند التدوير، لا يبدو "كائنات" صحيحة - تجاوز كائنات أسرع من كائنات أوثق، مما يمر في منتصف الشاشة.

لذلك: هل هذا صحيح؟باستخدام إحداثيات اليد اليمنى، إذا كان هذا يهم؟ giveacodicetagpre.

شكرا.

Answer 1

I see a couple of problems. First, the argument to tan() should be converted from degrees to radians.

Second, the formula for perspective projection in OpenGL is a little different from yours. As specified here, it uses 'near - far' in the denominator instead of your 'far - near'. The numerator terms are also different. Modifying your function slightly and converting from Java to C, I produced a projection matrix identical to the one given by gluPerspective() with the following:

static void my_PerspectiveFOV(double fov, double aspect, double near, double far, double* mret) {
    double D2R = M_PI / 180.0;
    double yScale = 1.0 / tan(D2R * fov / 2);
    double xScale = yScale / aspect;
    double nearmfar = near - far;
    double m[] = {
        xScale, 0, 0, 0,
        0, yScale, 0, 0,
        0, 0, (far + near) / nearmfar, -1,
        0, 0, 2*far*near / nearmfar, 0 
    };
    geom_matrix4_copy(m, mret);
}

Answer 2

For questions such as this one I would suggest an excellent resources: https://www.scratchapixel.com/lessons/3d-basic-rendering/perspective-and-orthographic-projection-matrix It really goes in the detail of the projection matrix. They are more lessons on the topic of camera, constructing camera rays, etc. You will need to do some digging.