No, the camera may be far away from the portals but still in-between them.benelot wrote:Produce a convex hull out of the eight corners of both portals. In your case it basically means you create a box out of these eight corners of which two sides are the portals. Now you can use a convex hull algorithm which tells you if the point the camera is located in is within the box (or in general the convex hull). If it is within the hull, it is between the portals. There are plenty of convex hull algorithms out there, just google "check if point is in convex hull".
Code: Select all
float PlaneDist(vec4 plane, vec4 pt) {
vec4 d = plane * pt;
return d.x + d.y + d.z + d.w;
}
Good idea as could calculate if it is rotated more than 180 first then do the planes equation.ktfh wrote:use planes to represent the portals, a single signed distance calculation can determine if the camera is inside or outside
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float VRenderManager::getDistance(glm::vec3 p0, glm::vec3 p1, glm::vec3 p2, glm::vec3 p3)
{
GLfloat a, b, c, d;
a = (p2.y - p1.y) * (p3.z - p1.z) - (p2.z - p1.z) * (p3.y - p1.y);
b = (p2.z - p1.z) * (p3.x - p1.x) - (p2.x - p1.x) * (p3.z - p1.z);
c = (p2.x - p1.x) * (p3.y - p1.y) - (p2.y - p1.y) * (p3.x - p1.x);
d = -p2.x * a - p2.y * b - p2.z * c;
return (a * p0.x + b * p0.y + c * p0.z + d) / sqrt(a * a + b * b + c * c);
}