I implemented an Arcball module to rotate the model using OpenGl. But I dont know how to support that arcball module to change the viewing directions.
How can I support viewing directions with Arcball rotation?
There are many ways an arcball could manipulate the view. What are your readings from the arcball?
glRotate on the viewing matrix or the model matrix portion would be appropriate. Setting the rotational 3x3 of either matrix based on the trackball input would also work.
I expect you have several options for input using the trackball. Which do you plan to use?