Csdrhrt

I have 2 Points which has x,y,z let's say from and to I am drawing wall between them using ARkit ios

To draw wall I use static height let's say 5 Meters

    node.position = SCNVector3(from.x + (to.x - from.x) * 0.5,

                               from.y + height * 0.5,

                               from.z + (to.z - from.z) * 0.5)

now I use following code to set angles

       // orientation of the wall is fairly simple. we only need to orient it around the y axis,

        // and the angle is calculated with 2d math.. now this calculation does not factor in the position of the

        // camera, and so if you move the cursor right relative to the starting position the

        // wall will be oriented away from the camera (in this app the wall material is set as double sided so you will not notice)

        // - obviously if you want to render something on the walls, this issue will need to be resolved.



    node.eulerAngles = SCNVector3(0,

                                  -atan2(to.x - node.position.x, from.z - node.position.z) - Float.pi * 0.5,

                                  0)

And I am rendering video into the wall.

Issue is If I draw from point1 to point2 (drag to right) Video is perfectly fine. But I start from point2 to point1 video is flipped because ofeulerAngles is different in both case

Angle point1 to point2 --> (0.000000 -1.000000 0.000000 3.735537)

Angle point2 to point1 -- > (0.000000 -1.000000 0.000000 0.478615)

Here is uploaded images of result

https://stackoverflow.com/questions/53282351/arkit-add-2d-video-flipped-by-x

Any help would be appreciated.

I have fixed issue with temporary solution still looking for a better one

Issue is of wall. wall is flipped other side of camera when draw from right to left direction. I have figure it out by setting isDoubleSided = false and by applying a image as diffuse contents which has text and I can see that image is flipped itself.

I have tried many things but this one helps me

1. Normalize vector


2. Find the cross between to SCNVectors


3. If y > 0 I just swapped from and to Value

Code

    let normalizedTO = to.normalized()

    let normalizedFrom = from.normalized()

    let angleBetweenTwoVectors = normalizedTO.cross(normalizedFrom)



    var from = from

    var to = to

    if angleBetweenTwoVectors.y > 0 {

        let temp = from

        from = to

        to = temp

    }



// Inside extension of SCNVector3

func normalized() -> SCNVector3 {

    if self.length() == 0 {

        return self

    }



    return self / self.length()

}



func cross(_ vec: SCNVector3) -> SCNVector3 {

        return SCNVector3(self.y * vec.z - self.z * vec.y, self.z * vec.x - self.x * vec.z, self.x * vec.y - self.y * vec.x)

    }

Hope it is helpful. If anyone know better solution please answer it.