View Full Version : Help With IBL and Tracked Footage

06 June 2007, 03:39 AM
Ok, i tryed to do this myself, with no luck.
I have tracked footage of my driveway, no problem there, i have it imported into maya nad everything is fine, so i plan on puttin a car i modeled into the shot, got it all put in, and set up, i used a picutre of around my driveway to make the right reflections on the car. I made a dome and applyed the image to a surface shader. So i Render out a test frame and everything works.
But i trying to put it all together in after effects, so how do i get just the car to render out, with the reflections, without the dome showing, or my images plane.
so just to clear it up, i want JUST the car, with all the lights and reflections, so i can add the car onto the video inside After Effects.

Thank you to anyone who can help me

06 June 2007, 11:07 AM
You have to make the dome : Primary Invisible in its render stats.
For the imagePlane You can just delete it or make it invisible, but if you are using it to get refractions or reflection that would be tricky. I wasn't able to acheive this so if anyone knows please shed some light over here. As a workaround, render again a matte pass to use it later in After Effect.

06 June 2007, 01:52 PM
My little workaround is to parent a plane to the camera, move it between the scene and the Image plane, scale it, so that the whole Imageplane is covered by it. (by Parenting it to the camera it is ensured that the plane moves like a second Image plane according to the movement of the Cam.)

In the shape-node I uncheck all except primary visibility,visible in refraction/reflection. Same in the mental ray settings (uncheck final gather cast/receive etc.)

then asign a use background Material to it, set all the Use Background Attributes to zero and mental ray Occlusion Mask as well if you render with FG.

This setup will render an Image with the Imageplane visible in Rendering but not in the Alphachannel

I hope this helps

06 June 2007, 02:54 PM
Ok, that solved one problem, thanks
heres the other one, when i render out an image of the car and put it into After Effects. the black backaround stays, and i cant get it out, but i know you gotta choose the colour for the AE to take out and i did that, but the black is till there, but in the air ducks on the car, you can see little slices thought them, and see the under layer, so im quite confused. It looks like its takeing out the wrong thing, or osmething.

Should i use a a plane for the car to sit on or something, and to add shadows and stuff. This is my first time tracking stuff, and it's giving me alot of trouble :banghead:

If you have any idea how to do this please help, even if you only know how to do a small part, that will still be very helpful
Thanks again

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06 June 2007, 02:54 PM
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