New in Cinema 4D R19: Recreate your Filming Location with Scene Reconstruction


In this Cinema 4D Release 19
Quick Start, I’m going to show you how to use the new reconstruction tab
in the motion tracker object to create 3D geometry from
this source footage. Before you can reconstruct
the geometry of your environment, you have to first track your footage.
And I accomplish that in this scene by using the full solve method.
So, it was basically a one click solution to get my initial 2D tracking points,
and even to generate all of these 3D nulls that you
see in my scene. Now, after I generated those nulls,
I went in and I adjusted the orientation of my scene with this planer
constraint. I positioned it at the world origin with this position constraint, and
I even adjusted the scale with this vector constraint. And I did all of this so that
if I was to add a figure object to my scene and press play, it would be
appropriately sized and more or less locked in place. Now, if you add an object
to your scene and you find that it is slipping quite a bit, that means you need
to go back and get a better camera track before you attempt
reconstructing your scene. So, I now have this good
track and I’m going to go to the reconstruction tab here.
And it’s basically a one click solution. You choose the level of quality that you
want and choose run scene reconstruction. In the lower left hand corner, you’ll
get a status update of what’s going on, and sometimes you might see that some
of these steps are repeating, and that repetition is controlled here
by the iteration setting. For the preview though, we’ve
only got one iteration, so this should be relatively quick, at least by
the standards of scene reconstruction. All right, our preview has finished
and what we get is a scene point cloud object. This is a polygon object
that has no polygons, it just has points. And each of these points has a color
assigned through this vertex color tab. So, if I playback through
my scene, we will see, well, at least from your perspective,
probably not much. The video compression is probably going to crush this pretty
brutally. So what I’m going to do is hide my auto features and I’m going to pop out
of my soft camera so we can look at these reconstructed points. And you’ll see
that these more or less look like the nulls we that we had previously,
but they’ve got some color applied. Now, this indicates to me that we
are going to be able to get a solve period. And that’s really the main thing
you’re doing when you use the preview mode. You’re just trying to establish that
you can create any geometry whatsoever. And that’s an important step because
some footage is just not going to reconstruct well. Generally because
there’s not enough texture on your surfaces or lighting is too difficult or
it just can’t track what’s happening in between frames. So, what I want to do now is see
what this might look like as a mesh. And this is a good way of working.
So, what you want to do is first generate, often in point cloud only, to figure out
if you’re getting a good density of points and once you’ve done that, choose
generate mesh. And that’s going to take a few moments to go back in and
calculate how all of these pieces should fit together. And what you’ll get back
is, at least with the preview mode, something like this. And we see that this
tree is really successful in being created and that’s because it’s got a lot of
really high frequency detail in the bark here. It’s got very clear but
very distinct patterns that are going to be easy to recognize
from multiple angles. So, now that we’ve got a sense
that this is going to work, what I want to do is change my preset here from
preview to medium quality and then I’m going to click on generate mesh.
All right, now that that calculation has completed, we can play back
our footage and see how well our scene has been reconstructed. It seems like our geometry is
tracking quite well with our footage, no significant slippage. I think this
will be good for us to work with. Now, our display is just a little bit
messy, so I’m going to ALT or option-click to hide my auto features here
and I’m going to hide my point cloud as well. And what are some ways that
we can now render this geometry? Well, probably the simplest way is to take
your motion tracker, go to the footage tab and choose create background object.
What that’s going to do is create a background object
and apply a material to it that’s got a frontal projection. I can now duplicate this material
and place it on my scene mesh. And when I play back, you’ll see that our
footage is being live-projected onto our geometry. And it looks, more or less,
like we want. If you want, you can go in there and add in a smoothing deformer,
in order to soften out some edges. And if you were to add in a compositing
tag, it would make this a compositing background, you’d have a good
starting point for shadow catching. Now, what if you want to
render this without projecting your footage back onto it? Well, for that, we
have this vertex color tag which allows us to see the color that has been
stored at each and every vertex, but this does not render by
default. So what we have to is create a material that will hold that vertex tag. So, in my color channel, I’m going to
go to texture and create an effect vertex map shader. And from here,
I’m going to drag in my vertex color tag, drag this onto my mesh. And I guess
I can call this “vertex color.” So, now when I render, we’re
going to see a color applied to each and every vertex. Now I am seeing a little bit
of specular highlight which I will kill and re-render here. And again,
we are seeing this vertex color. Now, this is not as detailed
as projecting your video back onto the surface of your object and that’s
because it’s just storing a vertex color. It’s not storing texture information.
And that’s the process for converting your footage into geometry. You
can use this directly for simulating LIDAR scans, break it up for HUD
effects, smooth it out for collision geometry, and even use it as a reference
for more accurate polygon modeling. If you enjoyed this video, you may
want to check out the rest of our “New in Cinema 4D Release 19” series on
cineversity.com, or you can subscribe to hear more about new videos
as we release them.

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