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