Issue with 3d rotation along the X axis

Question

I'm working on a project that required a 3d cube to be rotated along 3 axes. The cube is made up of 12 triangles, each with an instance of the Triangle class. Each triangle has a p0 , p1 , and p2 with the type sf::Vector3f . The triangles also have a float* position and a float* rotation . The position and rotation of a triangle is updated using this method.

void Triangle::update() {
    position;

    p0 = originalP0;
    p1 = originalP1;
    p2 = originalP2;

    sf::Vector3f rotatedP0;
    sf::Vector3f rotatedP1;
    sf::Vector3f rotatedP2;

    // along z
    rotatedP0.x = p0.x * cos((*rotation).z * 0.0174533) - p0.y * sin((*rotation).z * 0.0174533);
    rotatedP0.y = p0.x * sin((*rotation).z * 0.0174533) + p0.y * cos((*rotation).z * 0.0174533);
    rotatedP0.z = p0.z;

    rotatedP1.x = p1.x * cos((*rotation).z * 0.0174533) - p1.y * sin((*rotation).z * 0.0174533);
    rotatedP1.y = p1.x * sin((*rotation).z * 0.0174533) + p1.y * cos((*rotation).z * 0.0174533);
    rotatedP1.z = p1.z;

    rotatedP2.x = p2.x * cos((*rotation).z * 0.0174533) - p2.y * sin((*rotation).z * 0.0174533);
    rotatedP2.y = p2.x * sin((*rotation).z * 0.0174533) + p2.y * cos((*rotation).z * 0.0174533);
    rotatedP2.z = p2.z;

    p0 = rotatedP0;
    p1 = rotatedP1;
    p2 = rotatedP2;

    // along y
    rotatedP0.x = p0.x * cos((*rotation).y * 0.0174533) + originalP0.z * sin((*rotation).y * 0.0174533);
    rotatedP0.y = p0.y;
    rotatedP0.z = p0.x * -sin((*rotation).y * 0.0174533) + originalP0.z * cos((*rotation).y * 0.0174533);

    rotatedP1.x = p1.x * cos((*rotation).y * 0.0174533) + originalP1.z * sin((*rotation).y * 0.0174533);
    rotatedP1.y = p1.y;
    rotatedP1.z = p1.x * -sin((*rotation).y * 0.0174533) + originalP1.z * cos((*rotation).y * 0.0174533);

    rotatedP2.x = p2.x * cos((*rotation).y * 0.0174533) + originalP2.z * sin((*rotation).y * 0.0174533);
    rotatedP2.y = p2.y;
    rotatedP2.z = p2.x * -sin((*rotation).y * 0.0174533) + originalP2.z * cos((*rotation).y * 0.0174533);

    p0 = rotatedP0;
    p1 = rotatedP1;
    p2 = rotatedP2;

    // along x
    rotatedP0.x = p0.x;
    rotatedP0.y = p0.y * cos((*rotation).x * 0.0174533) - p0.z * sin((*rotation).x * 0.0174533);
    rotatedP0.z = p0.y * sin((*rotation).x * 0.0174533) + p0.z * cos((*rotation).x * 0.0174533);

    rotatedP1.x = p1.x;
    rotatedP1.y = p1.y * cos((*rotation).x * 0.0174533) - p1.z * sin((*rotation).x * 0.0174533);
    rotatedP1.z = p1.y * sin((*rotation).x * 0.0174533) + p1.z * cos((*rotation).x * 0.0174533);

    rotatedP2.x = p2.x;
    rotatedP2.y = p2.y * cos((*rotation).x * 0.0174533) - p2.z * sin((*rotation).x * 0.0174533);
    rotatedP2.z = p2.y * sin((*rotation).x * 0.0174533) + p2.z * cos((*rotation).x * 0.0174533);


    p0 = rotatedP0 + *position;
    p1 = rotatedP1 + *position;
    p2 = rotatedP2 + *position;
}

This method works well for all axes except the X axis. The cube has two red faces intersecting the Z axis, two green faces intersecting the Y axis, and two blue faces intersecting the X axis. Rotating the cube along the Z and Y axes works fine. The cube is rotating around the red and green faces. When rotating along the X axis, the cube is not rotated around the blue faces, but rather the global X axis. Am I doing something wrong? Is it supposed to be this way? Is there any way to fix it? I searched all over and couldn't find anything helpful.

Answer 1

bro you did it all wrong. use this 3D point rotation algorithm . i know it is javascript but the math still the same