at last,
if you  have a transformation matrix(transformation from world coordinate to camera coordinate),composed of a rotation matrix and translation vector.
and what you do is to set the camera so that you can see the model in the origin world coord change.
Do you have some suggestions about the transformation with your Camera methods.? How to use Camera method so transformation changes,it is just like the camera changes and then we can see different sides of model.?

setRotationMatrix() ?? It is the Object3D's method ,not Camera's?
what i want is to keep the 3D model in the origin of  world coord .And let the camera move.
Although it is almost same with keep camera still and let model change.

what I do is AR based on no marker,a little like vofuria which you have said you nerver used in other topics integrated with jpct .
so with the transformation matrix ,I can different sides of a 3d model when phone camera in different pos and direction.
Is it more  complex to get angles which used in rotating camera.

and,what does the setBack() meaning .Is it the same purpose like setOrientation??
thanks!

if the model coordinate is x left ,y down,z out of the window which jpct's z is opposite.
should I has a tranformation between model coordinate and camera world coordinate using above method??
thanks!!

Hi,
   I have got a camera Extrinsic Matrix(transformation from world coordinate to camera coordinate) from PTAM which is 4X4 matrix：
   R|t
   0|1  R is a rotation matrix and t is a translation vector.
   what i want to do is : I load a 3d model ,and want to show it. When I put the camera in different position and different ditection ,I can see different side of the model,but the model is still in the origin position.
   I have tried camera.setBack() and camera.setPosition  this method ,and camera.setOrientation(),camera.setPosition() as another method ,but it does not reach what i expect.
   have you have some idea??
   many thanks!!
   yours better