我知道上面有一些很好的答案，但我想添加一个非常简单的解决方案来适应相机平截头体内的边界球。它假设您希望保持相机目标和前向矢量相同，并简单地调整相机与目标的距离。
请注意，这不会给你最好的拟合，但它会给你一个近似的拟合，显示所有几何图形，并且只在几行代码中，并且没有屏幕到世界的转换
// Compute camera radius to fit bounding sphere
// Implementation in C#
//
// Given a bounding box around your scene
BoundingBox bounds = new BoundingBox();
// Compute the centre point of the bounding box
// NOTE: The implementation for this is to take the mid-way point between
// two opposing corners of the bounding box
Vector3 center = bounds.Center;
// Find the corner of the bounding box which is maximum distance from the
// centre of the bounding box. Vector3.Distance computes the distance between
// two vectors. Select is just nice syntactic sugar to loop
// over Corners and find the max distance.
double boundSphereRadius = bounds.Corners.Select(x => Vector3.Distance(x, bounds.Center)).Max();
// Given the camera Field of View in radians
double fov = Math3D.DegToRad(FieldOfView);
// Compute the distance the camera should be to fit the entire bounding sphere
double camDistance = (boundSphereRadius * 2.0) / Math.Tan(fov / 2.0);
// Now, set camera.Target to bounds.Center
// set camera.Radius to camDistance
// Keep current forward vector the same
C# 中 BoundingBox 的实现如下所示。重点是 Center 和 Corners 属性。Vector3 是一个非常标准的 3 分量 (X,Y,Z) 向量实现
public struct BoundingBox
{
public Vector3 Vec0;
public Vector3 Vec1;
public BoundingBox(Vector3 vec0, Vector3 vec1)
{
Vec0 = vec0;
Vec1 = vec1;
}
public Vector3 Center
{
get { return (Vec0 + Vec1)*0.5; }
}
public IList<Vector3> Corners
{
get
{
Vector3[] corners = new[]
{
new Vector3( Vec0.X, Vec0.Y, Vec0.Z ),
new Vector3( Vec1.X, Vec0.Y, Vec0.Z ),
new Vector3( Vec0.X, Vec1.Y, Vec0.Z ),
new Vector3( Vec0.X, Vec0.Y, Vec1.Z ),
new Vector3( Vec1.X, Vec1.Y, Vec0.Z ),
new Vector3( Vec1.X, Vec0.Y, Vec1.Z ),
new Vector3( Vec0.X, Vec1.Y, Vec1.Z ),
new Vector3( Vec1.X, Vec1.Y, Vec1.Z ),
};
return corners;
}
}
}
