CG and invisibility
Posted: Sat, 20th Mar 2010, 6:59pm
Post 1 of 12
Creating invisibility....have created diffuse and alpha channel in my modeling software (Iclone),made sure not to move cameras, rendered and inverted in adobe premiere, placed in Visionlab but for some reason can't get clip to line up (diffuse and alpha channel. So when I select displacement the invisibility is not aligned with my CG character. Any suggestions would be appreciated. Thanks ...also instead of making alpha channel in my modeling software can this be done in VisionLab, would if possible save a step.
Posted: Sat, 20th Mar 2010, 7:15pm
Post 2 of 12
Reading another thread about invisibility, it offered a solution to mask each frame and i assume apply displacement to each frame ( or do you apply displacement to the overall frames). Is this necessary when using an alpha channel?
Posted: Sat, 20th Mar 2010, 8:11pm
Post 3 of 12
If your CG character has an alpha channel all you have to do is apply a displacement map to that character in Visionlab.
Posted: Sat, 20th Mar 2010, 8:54pm
Post 4 of 12
Thanks for your reply, I've previously used your suggestion but when displacement is applied the invisiblity is out of sync with the character as stated in my original post. Does this mean that I need to apply a mask around the character at each frame + the displacement?
Posted: Sat, 20th Mar 2010, 9:54pm
Post 5 of 12
Not at all. The alpha channel is there so that you don't have to apply a mask frame by frame.
When you render out of Iclone, just render the character with an alpha channel. You need that alpha channel it's very important. Don't invert it.
Try this on the timeline.
Layer 2. Character with displacement map added. Use Visionlab's displacement map filter so just import the character with alpha channel.
Layer 1. Background
Posted: Sun, 21st Mar 2010, 12:35am
Post 6 of 12
Thank you very much again for your reply, you mention "not to invert", when my character comes out of Iclone it has a white background with black character image (not yet alpha), its placed in an editor to invert these colors as Icone cannot do this ( black background and white character (alpha). Do you still recommend not to invert? Also are you recommending that the displacement be placed on the alpha rather than the diffuse? Thanks again
Posted: Sun, 21st Mar 2010, 1:14am
Post 7 of 12
Ah okay, I see why you had to invert, I didn't know you were doing it to the alpha channel. You can do the same thing inside of Visionlab if you need to.
What's the "diffuse" that you keep mentioning?
layer 3. character clip. object mask link to layer 2.
layer 2. alpha clip. invert grade filter. object mask link to layer 1.
layer 1. background.
Posted: Sun, 21st Mar 2010, 1:35am
Post 8 of 12
For lack of a better technical description, diffuse is the primary clip with full color or texture, background with character. The alpha channel would be the opacity. Thank you very much for your recommendations, I'm new to FXhome products, so I know I will have many more questions, glad that folks like yourself are available to help with the learning curve.
Posted: Sun, 21st Mar 2010, 1:56am
Post 9 of 12
I'm kinda new to 3D stuff myself.
So do you have 3 clips then?
Background, character and alpha channel? If I'm missing something... this next bit may not help but you never know.
The same principle is used in this tutorial.
Just pretend that the guy and background are your 3D renders. The green screen keying part is the alpha channel.
Follow the steps in my previous post and the steps in this tutorial.http://www.youtube.com/watch?v=ReFl9TYayZU
Posted: Sun, 21st Mar 2010, 2:36am
Post 10 of 12
Hello again, no actually I only have the background and alpha, I had the invisibility working but the alpha channel was out of sync with my main background and character. In my setting I have my main clip which has my background setting which is animated, which also contains my animated character. Picture a scene with several animated characters but only one of them will be made invisible. I've made an alpha clip which makes all other characters in the clip and all other props invisible, except the character (which is also animated) that i want to make invisible. When brought into visionlab both clips have to be in sync so the displacement filter will follow the animation of the character as he moves across the screen. Again my problem has been how to sync. Does the toolsets offer any solution. i.e, the work window controls that allow you to pan it around. Also I'm delighted at the prospect of maybe being able to create an alpha channel in visionlab, I assume you bring in your video, place it on the canvas and select alpha, can you select which objects in the scene you want to make alpha (may be asking for the moon here)lol, then i guess you place both scenes on the timeline?
Posted: Sun, 21st Mar 2010, 3:03am
Post 11 of 12
Oh wow, I see what you're saying.
You need to have the character that you want to be invisible rendered out with no background but with an alpha channel.
The character needs to be in it's own video clip with alpha.
The background and other characters need to be in their own video clip as well.
Just like in that tutorial. You need a background to be shown under the displacement layer, otherwise you're just going to have a cut out effect where your invisible character should be. See what I'm getting at?
There needs to be a background in order for you to even be able to see through the character.
So try rendering out your scene again butr in three video clips.
One video with your background and any characters.
Another with the character that you want invisible.
And the last one as the "black and white" alpha matte or channel.
Let me know if that makes sense.
Posted: Sun, 21st Mar 2010, 3:18am
Post 12 of 12
My bad, I must have misspoke somewhere in my explanation, I'd like the character rendered with the background and the other characters. You see this is but a single scene of a movie. In this scene of the movie a character turns invisible and sneaks up on another character. So it will be rendered out as one complete avi and then joined with other slips to make a whole. Hope that helps. This is just the process I'm going thru to make the scene, creating an alpha to block out the character while applying and using fx to apply displacement. Its just that for some reason the displacement shows on one part of the character while the other part of the character is visible. So i have a blurred character half visible and half displacement. Out of sync.