Forum: Carrara

Subject: Using Voodoo for matchmoving with Carrara?

rendererer opened this issue on Dec 29, 2006 · 8 posts

rendererer posted Fri, 29 December 2006 at 1:59 PM

I'm interested in playing around with matchmoving, but as a hobbyist I can't really spring for Syntheyes or Matchmover.

I've got Voodoo up and running... is there some way to convert one of Voodoo's export formats to one of Carrara's import formats? I've tried a utility called V2C, which I found mentioned here http://www.flash-lists.com/msg/30901.html and downloaded from here http://www.euqfiz.com.br/downloads/V2C.exe and I've had some success, but it's still not clear to me how to get 3D objects to align with the imported camera motion.

Has anyone done this?

mmoir posted Fri, 29 December 2006 at 9:22 PM

 Joe, 

  I am interested in this too, I sort of stopped looking for a way to get the Camera information into carrara from Voodoo  and was looking at Blender which Voodoo supports  I just have to learn blender .  
    
I don't know much about this yet , but I would follow these steps.

  1. Load the Voodoo tracking information into Carrara.
  2. Load the Image sequence in the back drop and make sure the "Show Backdrop" is on in the interactive render settings.
  3. Run the animation to see if the Camera in carrara works properly.
  4. Insert a vertex object on objects where you know your Carrara generated objects are going to cast shadows.
  5. Make these vertex objects Shadow Catchers  by going to the Texture room and Selecting "shadow catcher" from the lighting models.
  6. If you do an area render nothing shows up of our shadow casting object , but if a shadow is cast from a 3d object onto the shadow catcher  the shadow  will show up . Change the Light object properties to have the Shadow intensity to 50% so the backdrop image shows through.

For aligning the 3d objects , I think it is just placing the objects and tweaking . I did this for a still image and it worked fairly well.  I added the flying blocks in carrara against a still photo, here is the link to the video. It is in DivX format.
http://mmoir.cabspace.com/Free%20models/KitchClip2a.avi

 I will have to check out the links you gave and get back to you. Thanks for posting this  info.

Mike

rendererer posted Fri, 29 December 2006 at 10:43 PM

Thanks for your advice, Mike. I did steps 1-4, but that's where I sort of got stuck. When my camera moves, my object kind of tracks the image, but it's sometimes wildly off, probably because it's much closer or further in motion-tracked space than it should be. But I had a hard time trying to place the objects in the 3D space. Is it supposed to be possible import a cloud of points or something to act as a reference?

Plus, my imported camera is pointed downward, which makes it that much harder to imagine how to place objects (Is it possible to rotate the camera to a normal position for hundreds of frames?

In the meantime I tried Icarus, which has a nice set of motion tracking features too. But the V2C utility can't open the .ma files created by Icarus. So another obstacle.

I wish Eovia still existed. I could ask them.

mmoir posted Sat, 30 December 2006 at 8:20 PM

Joe , 

  I have downloaded the V2C utility  and am at where you are at . I can get the Camera moves from Voodoo into carrara and they match up to the background animation, I had to resize things a bit but it is close enough.    I rendered an animation with  blocks on the ground and there was only one noticeable time when the block moved out of sync with the background so I am happy about that.
  I too had the camera pointing towards the ground which made placing things a pain, I did group the Voodoo camera and the tracking points together then rotated the new group.  I had to use the numerical input  to rotate , using the manipulator  to rotate didn't work . It is still hit and miss but I got it to work so I am happy.

Mike

rendererer posted Sat, 30 December 2006 at 9:04 PM

I didn't see any tracking points when I did this... unless I have an incorrect idea of what a tracking point is. I just got a camera with lots of keyframes. Are tracking points some sort of objects or vertices in the scene? Did you do something special to make them appear?

mmoir posted Sun, 31 December 2006 at 12:28 PM

mmoir posted Sun, 31 December 2006 at 1:28 PM

Joe, 
  I will try this again, my wireless internet isn't working right so I am on dialup.  

The tracking points in Carrara I am talking about are similar to the Voodoo tracking points that you see while  Voodoo does a track of the image sequence.  You can try the following and see if  it helps.

1.Load you sequence of images in Voodoo.
2.Choose "Tripod" in the Move type field of the Sequence image window even if Free makes more sense

  1. Load the initial camera, make sure the FilmBack numbers match the Image size of the movie you are tracking.
  2. Perform the track, if you get an error message to refine the track ,  ignore it. Don't refine the track.
    5.Save to .ma script.
  3. Make sure to Choose "all points" in the 3d Fpoints area when saving the .ma script. It is a little hard to see if this is actually selected just make sure it is. 
    7.Use V2C to convert the .ma script to a syncar file.
    8.Open the Syncar file in Carrara and point to your original avi when it asks for the target avi.
  4. It should open in Carrara with the tracking points.

I don't know if this will work for sure but it might .

Mike

rendererer posted Sun, 31 December 2006 at 6:22 PM

Thanks again, Mike. I was able to import the cloud of points by using the "Save Tracker position as vertices" option in V2C - and the camera motion was completely different when I did that as well. But I still have a lot of trouble getting my objects positioned. I really hope the next version of Carrara will support a more widely available match moving format, so I don't have to do this finagling.

Anyway, back to finagling.