image creation

I have toon boom animate pro. when i use the 3D and click on the transform
key, an altering forms appears which is used in creating (houses etc.) this altering form works great in creating the above.(. called true space)
for some if i tried to use it with an image,( animale or human) as long as there is no background, it works great, as soon as there is a background installed and i manipulate the image on the backgrond, only half of my image
shows. removing the background, it works ok.
what am i doing wrong?

Your image is probably being cut off by the background. By default images are placed at 0,0. If you go to your top view and use your Maintain Size tool to move your background backwards, does your object reappear?