Blender and Voodoo Compositing

http://blenderartists.org/forum/clear.gifPlease, I need your help. I am working on compositing real life image with Blender generated images. I have been able to CORRECTLY track the camera with Voodoo and successfully imported into Blender but when I add my virtual image which in this instance is a car, it does not show up in the rendered image even though it is showing in the screen shot. I noticed that when I unpress ‘‘Do Sequence’’ in the render button, the CGI image shows up but the movie tracked by voodoo doesn’t and when I press the ‘Do sequence’’ the movie shows but the CGI Image doesn’t. I would have loved to include the .blend file but I can’t seem to find a way to do it.

Can anyone tell me what I am doing wrong. I even added a simple ‘‘CUBE’’ in the scene, yet it did not show up in the rendered image. I know this explanation may seem vague so if you would like the .blend file, please kindly provide a means for me to do so.

I think I should add for clarity that when viewing the screen shot, I am in the Camera view (Numpad 0)

THANKS

You need to add the 3D scene to the sequencer. Add a new strip, but instead of selecting a video clip from your computer, choose “scene” instead. You’ll need to put this new scene strip on a track higher than your background video and change its mode to alpha over.

Usually, this kind of compoiting is done with node, but you should be able to make it work in the VSE.

Thanks mate, it worked perfectly. I had to make a lil adjustment though. Instead of alpha over, it was alpha under that worked. Really appreciate your contribution.

Glad you got it working.

Hello mate, I am experiencing another problem. The car is now showing but I realised that the perspective of the car is not right. It seems bigger than the rest of cars in its row, possibly because of the pespective. I tried manipulating the camera lens in F9 but after getting my desired pespective, it does not reflect in the render. And once I close the render button, the camera lens self adjust to its original pespective.
My many mentors on this site, how can I ensure the camara lens stays after I have adjusted it. Thank you.

Instead of trying to change the camera, try adjusting the position of your model in the 3D scene. The point cloud should give you a pretty good idea of size and placement.