View Full Version : basic question about composites...

04-17-2008, 09:21 PM
I'm creating some objects in LW which I render out with alpha channel and load into SE. The background film footage is soft and grainy and I'm trying to add grain and soften the LW objects to match bg without adding grain, etc. to the bg film footage by using alpha, overlay option, etc. but I can't figure it out without affecting the bg. I even tried layering with seperate LW object and alpha with the effects in between. (I tried adding effects in LW and compositing there but I had the same problem of the effects showing in bg.) Thanks.

04-18-2008, 05:44 AM
Hi - not to be unfriendly, but I think you'd be able to draw a lot more reposnse to this question in one of the LightWave forums. :)

04-18-2008, 05:56 AM
You would need to isolate the bg FROM the foreground elements to get it to work.
You can do some of it in SE because of the control tree but you will have to be quite patient with yourself to get it right.

How is your control tree activity affecting any other clip? One of the few ways I can think of that happening is if the foreground elements are without an alpha channel. Share what you are doing, if you don't mind, as I admit to being perplexed.

04-18-2008, 06:41 PM
I think I have attached the LW object with alpha and the background image (stills only) to this thread. I will have to look into the "control tree" features. As you can see I am just learning and this is my first post!

And SBowie, did you recommend the LW forum because you think it should be done in LW or because there is more feedback/support there?

I tried doing the compositing in LW but had the same problem of trying to roughen up the object without adding more grain, etc. to the bg and couldn't figure it out.


04-18-2008, 09:36 PM
I guess I couldn't upload tif or tga. I'll try to upload a zip file...

04-19-2008, 06:04 AM
And SBowie, did you recommend the LW forum because you think it should be done in LW or because there is more feedback/support there?Two reasons - first, this is really a compositing question, and SE - while cool enough - really isn't a compositor. Second, imho, the LW forums are full of guys with more experience at this sort of thing than this one. Whether with regard to LW techniques or an approach using one of the popular compositing apps, I think you'll find a deeper pool of knowledge on the subject there.

(Not trying to brush you off, just got a lot of respect for that crowd when it comes to this sort of thing ....) :)

04-19-2008, 10:30 AM

I think I may be able to do it in LW now that I give it more thought (I don't have After Effects). I need to get on the LW forum anyway. I'm trying to figure out why I don't see my SE codecs in LW and am wondering if it has to do with the fact that I am running LW in VISTA 64!

04-19-2008, 10:42 AM
.. to me it sounds a batch job in photoshop. WIth trial and error, you could do it in LW, but setting up an action on a folder of images in PS will probably yield a faster result ..

It depends of the qualities/lighting/dof you are describing vary alot during the footage.

05-29-2008, 03:16 PM
The problem is with the noise effect in SE (it is applied to all above it).
But, if you want to achieve the look in SE, add the noise amount to just the tower portion, LW rendered, clip.
Then blur it a little to match the c-ro clip.
I laid then next to each other and moved the time line back and forth to eye ball a match.
Now delete the background if you used it for side by side comparison and render the project using a file format with alpha channel enabled (I like HQ with alpha).
Remove all from project and load back in the background clip and the tower clip you just rendered.
Enable overlay and it should look close.
Select the tower clip and play with the color wheels to get the look you want.
Do not add blur as it will soften the noise you rendered in.
Make sure you go back and add more blur and noise as needed and re-render and bring back in.

PS You can have more than one SE open to speed this up.

Take care,

05-29-2008, 05:45 PM
....and SE - while cool enough - really isn't a compositor...

Oh, I don't know... It doesn't have all the bells and whistles of After Effects or Commotion, but with a little imagination, you can pull off some convicing comps.

I thought I'd try to solve the adding noise problem in SE. I took it for granted that the intent was to make that object on top of the mountain apear as if it is also in the distance and belongs there. Just adding noise by itself isn't convincing.

Here's what I did:

First, I did the usual and put the background (mountain) and object in the timeline and set the object as overlay.

Now, to add the noise, I added another instance of the mountain and overlaid (set to overlay) it over both the first mountain and the object. Then I set the alpha for the second moutain to 155.

Finally, I went back to the Object and and adjusted the contrast to try and match the mountain. I've included 3 examples of different contrast settings and a screen shot of the timeline in SE.

I think that by adjusting the contrast to your liking, and the alpha of the front mountain, you get the noise you want without destroying the background. Take a look and see if this is what you had in mind, BigSpider.

05-29-2008, 06:12 PM
Not bad, not bad.
I like my way better only because the grain is not doubled in any way.
That said, I tried your way and it looks good as well.

And although we found two ways of doing it, proving your point of a little imagination, I would do it in SE only if I had no choice as in no composite program.

Take care,