View Full Version : Compositing Help

Jack D
06-21-2009, 05:44 PM
O.K so Iím still new to Lightwave and I know that these are newbe questions , but Iím stuck and could use some help. I have my animation all done in layout and now Iím trying to render it out so I can composite in Aftereffects with the live action. Iím having 2 problem:
1) I canít figure out how to set the background to transparent. In the effects panel/compositing tab I have the back ground set to none, but it keeps rendering the back drop. I can change the color but not to transparent.
2) I canít set the right aspect ratio. I have it set to dv1 NTSC widescreen ( thatís the A.R I want) in render globals and in camera properties but I am still missing it some where.
I have done a search and found lots of cool stuff but I just need these two basic things. I'll take any help or if anyone can direct me to the right thread, that would be great. Thanks

06-21-2009, 08:19 PM
1) Are you rendering out 32 bit images? If you're doing 24 bit images there will be no alpha channel. When you say backdrop do you mean the sky/ground color gradient?

2)What is LW actually rendering out? If your camera is set up properly you shouldn't have to use the Render Globals.

Richard Hebert
06-21-2009, 09:44 PM
If you're rendering out an animation file instead of still frames make sure you're using millions of colors plus (the plus is the alpha channel). Still frames are better in the event of a "hiccup".

Jack D
06-21-2009, 11:01 PM
I have been rendering png 24bit. I'll try going with the 32 bit. What I'm getting is not the ground-sky garnet but the back drop color. By default its black and I can Change color but not to alpha. I'm not sure that my camera is set up right.
As far as the type of file(png and so on) is their one you think works best for compositing? And thanks for your help.

06-22-2009, 11:05 AM
Use the 32 png option. 24 png doesn't include the alpha channel. The extra 8 bits of info is the alpha channel.

I would keep the backdrop black but you could make it any color really. Just remember to pre-multiply against that color when you import into AE.

Jack D
06-22-2009, 04:31 PM
Thanks for the help with the background issue. The 32 bit PNG worked great.

Now, I am trying to set up my ground plan to not be visible to the camera, yet still show shadows. Again, I know this is basic stuff but I can't get it.

I am still trying to get the aspect to wide screen.

06-22-2009, 06:36 PM
Make a version of your ground plane with it's Alpha Channel set to Shadow Density. You can find this option in the Advanced tab in Surface Editor.

Are you using one of the resolution presets in the camera window?

Jack D
06-23-2009, 12:41 AM
hey Nick thanks for the help.
As far as the Preset res. I am using the D1 NTSC widescreen.

06-23-2009, 01:33 AM
Does the apsect value say 1.2? You won't see the distortion of the aspect ratio in the viewport btw, only in the render.

Jack D
06-24-2009, 01:21 PM
It does say 1.2, is that right or do I need to change it?

06-24-2009, 02:14 PM
No that's right. What does it come out like? Post an image -

Jack D
06-25-2009, 01:31 AM
In the Camera veiw it looks right but when it renders it's 4:3. I have been able to tweek it in Aftereffects, but I would rather render it correctly.

06-25-2009, 01:58 AM
That is correct, that's what you get with an aspect ratio other than 1. It gets reformatted to widescreen somewhere along the way to tv land, I did one tv show like that, but I'm not sure at what point it was fit to widescreen.

Jack D
06-26-2009, 06:05 PM
I guess that makes sense because it looks right after I manually fit it to the widescreen in After Effects. Those were my big problems and I want to thank you guys for the help. The next thing is trying to get the materials to look realistic. I'll post something new for that since it is off the original topic.