When I resize canvas my 3d text also resizes.
How do you stop the 3d text from resizing when canvas resizes???
Draw out the crop tool and then pull out one or more sides and commit the crop.
To expand the canvas on all sides press the alt (option) key and pull on one of the corner handles.
The downside is it's not as easy to expand by a certain amount.
right side of canvas expanded:
all sides expanded: