- [Instructor] Here's what's going on.
The UV project node is set for a planar projection.
Now the first issue is what is the plane of that projection?
Well, by default it's XY which means
here is my X axis, here in my Y axis.
It's like pushing it to the rear until it hits that wall.
Think of it as like a piece of cellophane
you're walking it toward the surface
and it'll just wrap around as you go around that surface.
Let me move my axis up here.
It is the axis that you use to
actually position the texture map.
That's its job, is to do the positioning.
But let's return to our original plane discussion here.
If I select YZ, now this is the Z axis
and the Y axis is vertical, that means
it's pushing it to the left, if you will.
And I can prove that by if I move it in Z,
you see I'm moving the map around
but if I move it in X, no change.
Y, of course will be affected.
And then the last option, get my UV project node back,
the ZX is projecting up from the bottom if you will.
(laughs) If we look down here we can see
ah yeah there it is, okay, there you can see.
I'm seeing it correctly from this point of view.
So that's the original projected plane.
Now, let's take a look at some
of the controls for positioning it.
I'm going to put it back to the default, XY.
And you use the axis to position and size it.
I'm going to put it to this, I can move it there.
If I want to see my wireframe, I can see how much is covered,
but that kind of makes me my axis hard to see.
What I do then, is I use the axis
to position it and also to scale it.
If I look at my wireframe, I can see
I don't have it covered out here
so I will just increase the scale
until I've completely covered all my geometry.
Again, this is a planar projection,
so it's coming in this direction here
which means it's going to streak on the sides
which are parallel to the projection direction.
My axis has other uses too.
Besides scaling and positioning,
I could, if I wish use the axis to do this.
I could rotate it in Z, how about that huh?
Or I could apply a skew to it.
To be sure the UV project node itself
has some controls over the maps position.
One thing you're going to want to know about,
are these right here Invert U, Invert V.
Invert U is going to flop it horizontally like that.
Invert V is going to flip it vertically like this.
Alright, let's look at the spherical projection.
What that means is, it's going to take
the texture map and wrap it around a sphere
of infinite distance and then shrink it
until it starts hitting polygons.
That's the basic psychology of the thing.
Again, our axis node controls where it is
and the scale factors and this looks pretty rough.
Let me reset my axis to default.
The center of the scale is now down here
where my axis is so first thing I got to do
is move it to the center of the object.
It's a broad principle, you want to choose
a projection technique that is appropriate
for the shape of your geometry.
This is not a very spherical thing,
so this is not a terribly good
projection scheme for this guy
but it'll definitely illustrate a point.
An issue I want to call your attention to
is this hideous seam.
Look at that.
Ooh rude-o!
We don't want that hideous seam
so if you get the hideous seam,
what you want to do is rotate it
until it goes around the back side of the character.
Or the geometry or whatever it is.
I'm going to rotate it 180 degrees.
Now I'm looking at the front, there ya go.
I could bring down my uniform scale here
until I get my picture.
Now you see, I've run out of texture map
and it's gone semi transparent.
That's because I have a black outside node.
If I turn that off, the texture map
is just going to continue to streak to infinity.
I didn't want to do that.
That provides confusing results for the demo
so I trimmed the edges with black.
So that means my texture map is now
too small so I can increase the scale
until I've covered all my geometry.
If I want to bring this down, lower it down a little bit,
I can grab my Y value and bring it down
to get everything positioned just the way I want.
And of course, I can do all the rotates,
and the skews and other axis controls.
I wanted to talk to you about this ugly seam thing.
Here's something kind of weird about all of this.
If I project this on a sphere.
This is a real sphere, now I'm going to set the axis
back to default so it's at the center of the sphere.
It correctly does a spherical projection
exactly like you'd expect, except the ugly seam back here.
Again, I can rotate the sphere
or rotate the texture map to get it away from the camera,
but that means I can't circle around the spherical object.
If however, you let the sphere itself
do the spherical projection 'cause that's
the default UV texture map on the sphere.
There is no seam.
It works perfectly.
Oddly enough, I brought this to
the attention of the foundry and they were thunder struct.
They had never seen this before.
I don't know how, but okay! (laughs)
Alright, back to this and let's
look at the cylindrical projection.
Again, cylindrical is not terribly
well suited for this character, but it will serve the demo.
I've decided that I'm going to try the spherical projection
so I'm going to raise my axis and I have to have the axis
in the center of my character for spherical of cylindrical.
If I put the axis out here, that means
that the sphere or the cylinder is really centered out here.
So I'm not going to get a very good result.
So I need to have it in the center of my geometry.
Again, you're supposed to choose a projection method
that is appropriate for the shape of your geometry.
Again, the ugly seam I could do the rotate of 180 degrees
in Y to put it around the back side of the camera.
But you know the drill.
And the same thing happens with the cylinder.
If I switch in my cylinder geometry,
let me reset my axis back to origin.
I'm getting a correct cylindrical projection
around my cylindrical geometry, that looks good
but I've got the ugly seam and I will not have an ugly seam
if I let the cylinder do the projection itself.
No ugly seam.
Nuke's UV project node, only supports simple
UV projections like planar and spherical
because the assumption is, that the texture map
for a T-Rex for example, will be mapped
by the 3D software that built it,
or a texture painting program, such as Mari.
And again, Nuke's 3D world is designed
for rephotographing live action elements.