Camera looking in different direction

hello all
i have a 3d model on scene its a collada file
i also have the translation and rotation values of each camera points used to create the model
i am using these values to calculate the camera position and rotation and move the camera to that location to view that particular image on the 3D model

in the video : the 3d model is loaded
when i click on submit the parameters of image1 is taken and the camera is moved to that particular location

my camera is always looking at -z (negative Z ) Axis ,
the camera has moved to the right location and as image 1 is in view of -Z axis everything worked fine
you can see the camera location marked in red circle in the video
now as soon as i scroll in or out or click the camera is looking at the origin

image 2 :

when i load another image to view which we should see in x axis
i use the parameters of image 2 and calculate the camera point . when i click on submit(which sets the camera to calculated camera position ) we see that i get a blank screen and when i zoom out a little the camera is looking at origin . but with the camera point marked with red circle we can see that the camera position was correct but as it was looking in -z axis we could not see the model
and when i zoom out it look at origin and we can see the approx image view on the model
i want my camera to look towards the model after rotation .
i am using a perspective camera

camera.rotation.elements = R21.elements; //( 9 elements )
var cpt = new THREE.Vector3(_C21.x, _C21.y , _C21.z); //(_C21 vector has my camera position 3 elements)

camera.position.x = cpt.x;
camera.position.y = cpt.y;
    camera.position.z = cpt.z;