问题
I try to switch between Perspective and Orthographic cameras in my script. I want object on some depth to keep it's projection size. I gave up to understand the geometry...
Could you provide some link to a simple tutorial this is too complicated for me.
For object with position.z==0
i have:
perspCamera = new THREE.PerspectiveCamera(45, W / H, 1, 1000);
perspCamera.position.z = 100;
var S=Math.tan((45/180)*Math.PI)*100;
orthoCamera = new THREE.OrthographicCamera( -S, S, S, -S, 1, 1000 );
It is incorrect.
Update:
I get it I will post an answer with codepen link
回答1:
The relation between Z-distance and size, at perspective projection is:
var fov_y = 45;
var depht_s = Math.tan(fov_y/2.0 * Math.PI/180.0) * 2.0;
So the orthographic projection has to be (THREE.OrthographicCamera):
var Z = 100;
var aspect = W / H;
var size_y = depht_s * Z;
var size_x = depht_s * Z * aspect;
orthoCamera = new THREE.OrthographicCamera(
-size_x/2, size_x/2,
size_y/2, -size_y/2,
1, 1000 );
来源:https://stackoverflow.com/questions/48187416/how-to-switch-between-perspective-and-orthographic-cameras-keeping-size-of-desir