Hi,
How can I calculate affine transform between three pairs of the corresponding points?
I have 3 pairs of the corresponding points:
cocos2d::Vec2 ps1[3];
cocos2d::Vec2 ps2[3];
I need function
cocos2d::Mat4 getAffineTransform(const cocos2d::Vec2 ps1[3], const cocos2d::Vec2 ps2[3])
{
//compute mat4 for transformation
//ps1[0]->ps2[0]
//ps1[1]->ps2[1]
//ps1[2]->ps2[2]
//TODO:
return cocos2d::Mat4{};
}
and result pass to:
void Node::setNodeToParentTransform(const Mat4& transform)
To transform my cocos2d::Sprite
@stevetranby Thank you for answer.
Do you know how to exactly convert cv::Mat matrix 2x3 to cocos2d::Mat4 matrix 4x4?
Here’s the usage code and info:
https://docs.opencv.org/2.4/doc/tutorials/imgproc/imgtrans/warp_affine/warp_affine.html .
I don’t know for sure, but my guess is the 2x3 matrix it returns would be the upper left sub-matrix of the desired 4x4 transform matrix? It can’t give you rotation unless you had a 3rd input point that you used as the origin for rotation.
// getAffineTransformation's Matrix (2x3)
[[scale_x, shear_x, translate_x]
[shear_y, scale_y, translate_y]]
// if scale negative then it's also reflected
That’s about as much as I know without research/experimenting myself.
