How to I use ofCamera::screenToWorld to calculate positon on a plane

beginners
#1

I have a plane in 3d space. Every time a user clicks, I want to map the mouse location to a location on the plane, and then draw a sphere in that location. Help?

#2

You need to do a ray-plane intersection

screenToWorld will give you points on your pick ray

And then use intersection maths to see where the ray and plane coincide

You could use ofxRay for this

#3

Thanks for anyone else wondering this is how I mapped screen positions to a position on a x-z plane;

    ofVec3f screenToWorld = cam.screenToWorld(ofVec3f(ofGetMouseX(),ofGetMouseY(),0.0));
    ofxRay::Ray ray(cam.getPosition(),screenToWorld - cam.getPosition());
    ofxRay::Plane plane(ofVec3f(0,0,0),ofVec3f(0,1,0));
    ofVec3f pointOnPlane;
    plane.intersect(ray,pointOnPlane);
    ofLog() << pointOnPlane;
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