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View Full Version : 3d/live action compositing??? (mpan3, please comment if you read this)



vfxjunkie
23-Oct-07, 19:43
Sorry, I know that I have probably been unclear on the effect I wanted achieve with Blender, but what I am asking is how would I achieve an effect like this?(please go step by step)(mpan3, please comment if you read this)
http://youtube.com/watch?v=Hf5hoC_YkyI

HD render man
23-Oct-07, 21:01
ok well if you want to add a object into live action start like this.
make your object and set the globle mat to a total black color as blender uses the alpha to detect whether a object is there to be placed in to a video much like a green screen is used to remove an object in some other software.
so once you have done that go to the video sequence editor and add you scene and add your video or picture.
then select both the scene and the video and add a effect the effect you want is either a alpha over drop or a alpha under drop try both i cant remember from memory which it is. once you have done that you can see the result in the preview if you change the screen, or you can render it out by checking the do sequence under the render animation button.

edit
if you wish to add shadows i think you need to place a plane where the floor would be in your video, a good way to get it in the righ position is to add the video as your background while in camera view. once you have added the plane you need to set the plane so that it only shows shadows but does not show as a color there is a good bit of info about diong all the steps metioned in blenders wiki.
as for getting the camera to realisticaly follow the camera in the video then you need a camera tracker.
there is a free onecalled vodoo and a ple one called icarus which can be used for free for none profit projects.
hope this has helped post back if you get stuck

vfxjunkie
23-Oct-07, 22:26
ok. thanks. I will try to test this asap.

Postmodern_Boy
23-Oct-07, 23:26
yeah, for something like this you would definatly want to learn a camera tracker. I know peerless productions has a tutorial for Icarus (also check out some of his blender special effects videos, very inspiring stuff) and I think there is info for using Voodoo with blender right on the programs main site and it seems a lot of people are starting to prefer it over Icarus.

HD render man
24-Oct-07, 11:03
i would agree try to learn vodoo first as it is free for what ever plus its pritty good.
i did hear a few roumers about blender getting its own camera traker but i don't know whether it was true or when we could expect it.

Postmodern_Boy
24-Oct-07, 15:12
i did hear a few roumers about blender getting its own camera traker but i don't know whether it was true or when we could expect it.
I hope that happens, If blender got camera tracking and the green screen plug-in included it could be well on its way to becoming a special effects studio. :eek:

which reminds me. If your interested in live action compositing you will probably want to try green screening people into cg backgrounds eventually. this plug-in makes it much easier then setting up those crazy nodes.
http://paprmh.googlepages.com/greenscreen

and in case you are having trouble finding voodoo, heres the link.
http://www.digilab.uni-hannover.de/download.html

vfxjunkie
24-Oct-07, 23:35
thank you guys for all your help! I will try to learn voodoo because i too have heard many people say that they prefer voodoo over icarus.

vfxjunkie
24-Oct-07, 23:42
Also, to add audio to a composite, wouldn't I just have to save it as an avi. file and then add the audio?

chipmasque
25-Oct-07, 10:21
Also, to add audio to a composite, wouldn't I just have to save it as an avi. file and then add the audio?A/V mix outputs directly from Blender are limited, but you can use the VSE to synch up your audio track(s) and your composite, then export an audio mixdown as a .wav file for final mix in an app like Virtual Dub.

Avoid using the VSE to split your recorded audio/video, however (you can do it in Virtual Dub instead), 'cause there's a bug that can distort the audio track pretty badly if the source is .avi.