three 基础库
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import {
MathUtils,
Quaternion,
Vector3
} from '../../../build/three.module.js';
const _va = /*@__PURE__*/ new Vector3(), // from pe to pa
_vb = /*@__PURE__*/ new Vector3(), // from pe to pb
_vc = /*@__PURE__*/ new Vector3(), // from pe to pc
_vr = /*@__PURE__*/ new Vector3(), // right axis of screen
_vu = /*@__PURE__*/ new Vector3(), // up axis of screen
_vn = /*@__PURE__*/ new Vector3(), // normal vector of screen
_vec = /*@__PURE__*/ new Vector3(), // temporary vector
_quat = /*@__PURE__*/ new Quaternion(); // temporary quaternion
class CameraUtils {
/** Set a PerspectiveCamera's projectionMatrix and quaternion
* to exactly frame the corners of an arbitrary rectangle.
* NOTE: This function ignores the standard parameters;
* do not call updateProjectionMatrix() after this!
* @param {Vector3} bottomLeftCorner
* @param {Vector3} bottomRightCorner
* @param {Vector3} topLeftCorner
* @param {boolean} estimateViewFrustum */
static frameCorners( camera, bottomLeftCorner, bottomRightCorner, topLeftCorner, estimateViewFrustum = false ) {
const pa = bottomLeftCorner, pb = bottomRightCorner, pc = topLeftCorner;
const pe = camera.position; // eye position
const n = camera.near; // distance of near clipping plane
const f = camera.far; //distance of far clipping plane
_vr.copy( pb ).sub( pa ).normalize();
_vu.copy( pc ).sub( pa ).normalize();
_vn.crossVectors( _vr, _vu ).normalize();
_va.copy( pa ).sub( pe ); // from pe to pa
_vb.copy( pb ).sub( pe ); // from pe to pb
_vc.copy( pc ).sub( pe ); // from pe to pc
const d = - _va.dot( _vn ); // distance from eye to screen
const l = _vr.dot( _va ) * n / d; // distance to left screen edge
const r = _vr.dot( _vb ) * n / d; // distance to right screen edge
const b = _vu.dot( _va ) * n / d; // distance to bottom screen edge
const t = _vu.dot( _vc ) * n / d; // distance to top screen edge
// Set the camera rotation to match the focal plane to the corners' plane
_quat.setFromUnitVectors( _vec.set( 0, 1, 0 ), _vu );
camera.quaternion.setFromUnitVectors( _vec.set( 0, 0, 1 ).applyQuaternion( _quat ), _vn ).multiply( _quat );
// Set the off-axis projection matrix to match the corners
camera.projectionMatrix.set( 2.0 * n / ( r - l ), 0.0,
( r + l ) / ( r - l ), 0.0, 0.0,
2.0 * n / ( t - b ),
( t + b ) / ( t - b ), 0.0, 0.0, 0.0,
( f + n ) / ( n - f ),
2.0 * f * n / ( n - f ), 0.0, 0.0, - 1.0, 0.0 );
camera.projectionMatrixInverse.copy( camera.projectionMatrix ).invert();
// FoV estimation to fix frustum culling
if ( estimateViewFrustum ) {
// Set fieldOfView to a conservative estimate
// to make frustum tall/wide enough to encompass it
camera.fov =
MathUtils.RAD2DEG / Math.min( 1.0, camera.aspect ) *
Math.atan( ( _vec.copy( pb ).sub( pa ).length() +
( _vec.copy( pc ).sub( pa ).length() ) ) / _va.length() );
}
}
}
export { CameraUtils };