Boujou to max, sliding issue ..

[eodmpink]

I think you're scene plane in Max is not aligned correctly.

Like you said, it looks as if the right side of the building and the shadowpass plane slides but the left side of the building is pinned, this leads me to believe the right side is behind/under the actual footage plane.

So looking at the later frames, I think the building is tilted (with the left side of the building as the pivot point) more to the right than it should be.

[everlite]

Thanks,

I kind of understand what you mean but feel a little unsure how to correct the issue because i've tried previously moving the box around and it would always slide. Is there any way to get this process bang on correct?

Just check over the following and let me know if this seems correct?

From Boujou i exported the script to max, this imported the cam and tracks, pointing down. I created a dummy and linked everything to the dummy then rotated this until it seemed correct. I then loaded the seq and create a box, i aligned the box to the track that references the position where i want it to be in the plate.

So that's pretty much it. I've uploaded the Max scene, please take a look and let me know if what you suggest is the case:

http://www.capturefx.co.uk/web/snow.rar (http://www.capturefx.co.uk/web/snow.rar) (3.2mb)

I've only included the first, middle and last frame due to the size of the plate.

However you can download the full plate at:

http://www.capturefx.co.uk/web/seq2.rar (http://www.capturefx.co.uk/web/seq2.rar) (263mb)

Thank again, hope you can shed further light on this :)

- Dave.

[eodmpink]

Much of this you already know and tried, but just to be sure:

i've tried previously moving the box around
Are you talking about movement in all axises plus rotation?

Is there any way to get this process bang on correct?
Try creating test objects in Boujou that fit the track and export out the objects with the tracks and camera to Max.

i aligned the box to the track that references the position where i want it to be in the plate
Boujou (and all cam trackers) most always creates feature tracks that are misleading due to the algorithms guessing where they are to match up with the rest, so trusting them 100% is no good.

That's all I can think of, so if none of my suggestions are helping then try reffing Tim Dobbert's Matchmoving: The Invisible Art of Camera Tracking, or VFXTalk.com, or Boujou's customer service/forums; all of them are superior to cgtalk in regards to tracking knowledge IMO.

[everlite]

Thanks for your help, yes i have Tim Dobbert's book, it's been very good so far. Please take a look over my most recent test and tell me if this looks solid?

http://www.capturefx.co.uk/web/snow6a.mov (http://www.capturefx.co.uk/web/snow6a.mov) (6mb QT)

Cheers - Dave

[Piek]

Hi, I've scrubbed back and forth a few times and the polys seem to be locked. I find that when testing camera matched scenes, my eyes kind of 'will' the CG elements into sliding, making it difficult to be 100% sure :o)

Nice bit of footage, your own? or stock?

[everlite]

Thanks, yeh i know what you mean :) Well glad i accomplished that one, i'm going to set in a cg building now see how well i can comp it together.

Yeh great footage, wish i did take it myself, i puchased it from www.istockphoto.com (http://www.istockphoto.com) well worth checking out :)

Thanks again - Dave.

[charbel20]

hy everlite

thanks for this post but can you give us the footage of the snow and we can work on it?

plz

[everlite]

No, sorry. visit www.istockphoto.com (http://www.istockphoto.com)

[charbel20]

hy again everlite

thanks for your reply.

in which software you have added the box?
and which renderer you have used?

and if you have a tutorial for this?

would you plz post or the website.

i have a problem of alignement in 3ds max. i hope you can help

[everlite]

go to www.simplycg.net (http://www.simplycg.net) > video tutorials > boujou.

A guy did a pretty sound tutorial using the same footage.

- Dave.

[charbel20]

thanks everlite for your fast reply

but i have a problem with the cg element,it still move with the camera up and down,it's not stable on the ground

you can look on the footage and see the problem.

can you help me?

thx

[everlite]

Your zip produced an error when i tried to open it.

There's no one set method to fixing a sliding object, to begin with you need to get a solid track from boujou, then when you take the data into Max you need to recreate the scene in 3d and move this around until you get it positioned tightly.

I should say that this is one of those things where you really do get out what you put in, if you have a good high res plate to begin with, good feature tracks and accurate measurements it makes it all the more easier, without all that you gonna struggle quite a bit.

Lots of fine tuning and good resources to begin with.

Post up the zipped file again.

- Dave.

[everlite]

http://www.simplycg.net/viewtopic.php?t=3616

The tutorial on that page really is a great intro to the subject.

[charbel20]

this is the zip file
thx

[everlite]

Ok, a few things that i'd do to begin with, first off stop the bending, that's just WAY too distracting when trying to match up the plate.

Next evaluate the track data, (i'm guessing you're using boujou) did it track well? the tree would cause a little concern for me, either it'd work really well and help or completely screw up your data and throw you off.

I'd probably go back into boujou and mask out the tree, keeping as tight as possible.

Then once you get the data into Max i'd begin by laying out the scene based on the points (from boujou) using the house you should be able to make out the general shape in max and use that as a starting point to add in a simple box and roof for the house itself.

Next lay in a plane for the ground and just start laying out other features, it's worth noting that alot of this process really is teaking until you get things aligned up.

other things you can try, use something like aftereffects to bump up the contrast when doing the original track.

Did you watch the video i linked too?

- Dave.

[charbel20]

did you mean the video tutorial at simplycg.com? no i didn't watch it yet but you snow footage i have watch it .

and in this video my problem is solved?

thx

[everlite]

Did you read the rest of my response?

What you need to understand and seem to be failing to understand is that there is no one single answer to your problem, it involves lots of tweaking and understanding how things work up and down the process and how they effect each other. The video tutorial that i linked you to will help to develop your understanding of the process and in turn help you understand the best way to fix your problem.

I highly recommend you watch the video tutorial.

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