Today I'm going to be showing you how to do some camera mapping but also how to bake in

the textures from that camera projection.

So I have this photo that we're going to be using for this tutorial.

We have essentially what is a box and then a bunch of stuff in the background.

And the main idea is we're going to do some camera mappIng.

So we're going to have a camera over here.

And then a box that you know pretty much matches this box.

We are going to project this image from the perspective of that camera on to that box.

But then the new step is we want to have this box have any custom uv map we want.

So we can unwrap it however we want.

And then we want to bake the textures onto that uv unwrap.

So unlike the projection, here we're going to have a custom uv map and bake it on to

there.

So again, the first step is to do some camera mapping.

And I did cover this in a previous tutorial.

So I'm going to do it.

But I'm going to do it very quickly.

If you want the full details there is a link in the description to the full tutorial for

camera mapping.

But this should be pretty quick.

We're going to open up fspy to get the camera in the correct perspective.

Use this photo right here.

And then we just need to match up our x and y axes.

So I'm going to turn off dim image so we can actually see what we're doing.

We can have the y axis be along here and then the x axis be along here.

Which is going to be really easy to set up because of course we have this box.

So y axis.

I'm just going to grab this handle and hold shift to get this zoomed in perspective.

So again handlebar and then hold shift to get that zoomed in mode.

And then of course we need 2 of these so it makes sense to have one y axis going here

and then the other one going up here.

We know they're parallel because they're part of the same box.

So put one here.

And also put one, where is it?

Let me try that again.

And also put one here.

And then for the x axis same thing but in this direction.

Again I'm doing this very quickly because I did cover it before.

But I just want to make sure these fundamentals are still here.

Think it's important.

Put our other x axis over here.

Just like that.

And then once we're happy with this we can turn on our 3d guide and set it to xy.

Because you know x and y axis. xy grid floor.

And then we're going to take what's going to be the world origin in blender.

We're going to take it and then just move it down to the corner.

Holding shift so we can see what we're doing.

Ok perfect.

So when we import this into blender we're going to get a scene with this background

and then the world oriented correctly with this camera in the right perspective.

And then the origin is going to be in this corner.

So let's do file.

Save as.

And then I'm just going to call this projection.

And we're going to import this into blender.

So I'm going to open up blender and of course you also need the plugin which again is free.

All this is covered in the first tutorial.

We need the plugin to import fspy files.

So I'm going to delete this camera.

We don't need it.

We don't need this light.

And I'm just going to keep this cube right here.

So file, import, fspy.

And then just navigate to wherever you have it.

Ok so it set up our background.

It set up our camera.

And then you know the world origin is in the corner of the box.

So the first thing we're going to do is we're going to save with control s.

And then desktop.

And let's call this thing, let's call it bake camera projection.

Because you know this is what this tutorial is about.

We're going to bake the textures.

I'm going to go into our camera.

Go into camera parameters.

Background images and make this brighter.

So we can see what we're doing.

And then the first thing to do is to take this box and align it so that it matches with

this box.

So I'm going to take the corner, which should be this corner.

And put it in the corner of our main box in the image.

And luckily we have this set up very nicely.

So we can just g for grab.

Z axis and move it up by 1.

And then same thing for the x axis.

So g, x, 1.

All keyboard shortcuts are going to be up here.

And then g, y, 1.

And let's see if that did what we wanted.

Ya perfect.

So of course we need this to be wider longer and taller.

Which shouldn't be a big deal.

We'll go into edit mode with tab.

Select this face.

Again face selection with 3.

And then we just move this until it seems right.

So g and then x.

And it doesn't have to be perfect.

We can do a bit more aligning later.

Take this face and then move it down the y axis.

And then we just need to take this face and bring it up so it's using up the whole box.

So g and then z.

Until that looks about right.

And here you see the error starting to accumulate as we go higher and higher and higher.

You can see this little gap.

And we can just adjust this by grabbing from this perspective.

And just trying to fix that a little.

So no it's not perfect.

It's a bit of a slanted cube.

But honestly I think it's going to be good enough.

We can do a bit more correction.

Something like that.

So ya technically it's a slanted cube.

But this should be good enough.

So we are pretty much almost at the end of what was covered in the first tutorial for

camera mapping.

All we have to do is project the texture you know the background texture from this camera

onto the mesh.

So the way we're going to do that is we're going to select this.

We can call it, what can we call it?

We can call this thing original.

So this is going to be our original cube.

We can call our camera just camera.

And also one other thing is our background image.

Default when you export out of fspy it's going to call it something like this.

So I'm just going to call it projection image.

Just so we have some good naming conventions.

So in shading for our original cube.

What we're going to do is we don't need this bsdf.

So x to delete.

We're going to add an emission.

And this is going to be important later.

But we're going to do it with an emission.

Plug this in.

Plug it in like that.

And then if you do not have node wrangler enabled go to edit, preferences, add-ons and

type in node wrangler.

And you should have this on.

So make sure it's on.

And then one thing it lets you do very quickly is we're going to select our emission and

hit control t.

And it's going to give us all these nodes.

This node group we're going to move it back with g.

You can do it without node wrangler it will just take some time.

So we have texture coordinates set to uv.

Feeding into this mapping node which we're really not going to touch.

And then into this image texture.

And of course for this image texture we want you know the image we're going to project.

So we're going to use projection image which is already in there.

And you see that none of this is looking correct but that's because we didn't do any of our

projection.

It's just using the uv map.

So what we're going to do.

Let's go into lookdev mode.

What we're going to do is we're going to go into modifiers.

And then do the same thing we would have done before.

So originally what we would have done is done a uv project on our uv map.

From the camera.

And you see it's pretty much good to go.

We do have a bit of distortion.

Notice that the aspect ratio in this case is 1.

And that's because our image if we go into properties is 3456 by 3456.

So the aspect ratio is 1.

If you had something a bit more common like let's say 1920 by 1080.

You just divide the numbers and get your aspect ratio.

So in that case it would be 1.7 repeating.

And you just feed whatever number that is up here.

Into your aspect.

But in this case it is 1.

And you do it's a bit distorted and I'll show you exactly how I know.

So what we do, or what we would have done before is add in a subsurf.

Put it on simple so it doesn't you know turn into a sphere.

Bring up the divisions and then just bring this up.

So this without and then this is with.

So you see there is definitely some distortion.

If we go into our camera.

So with the subsurf we hide it and you see it looks perfect.

Instead if we did not have this and then do a hide you see that it really is heavily distorted.

So this is a necessary step.

And then the issue is if we wanted to bake it.

Originally the only thing we would have known to do is to apply these two modifiers.

And then you see when we go into edit mode we have way too much geometry.

We only want six faces.

And technically yes this is baked on.

It's sticking on to the mesh.

But not only does this have too much geometry that's just one issue.

The other issue is that if we go into our uv map.

I'm just going to set this as our background image.

Our uv map, it's essentially a frontal perspective projection.

It's not a good unwrap.

So if we had this box.

What we would do is have the normal kind of unwrap.

So for example I'm just going to import a cube and look at its uv map.

So here you see we have this cross looking thing.

And that's more so the kind of unwrap you would expect.

Of course not exactly the same since these faces are longer here.

It's not a perfect cube.

So we want to get the texture to still be wrapped correctly.

So it's still from the perspective of this camera.

But we want to make sure that there's not as much geometry and also that the unwrap

is better.

So this is not a good approach.

So we're just going to undo until we get these modifiers back.

There we go.

So I'm just going to close these.

So that is originally what we would have done.

So instead here is the trick for baking.

What you do is you go into object data and then uv maps.

So in our original object we're going to set a uv map and call it something like final

unwrap.

And what this is is it's going to be the unwrap that we would ideally want the texture to

be baked into.

So this is the final unwrap we want.

Not this mess from the perspective projection.

So let's actually set up this final unwrap.

So go to uv editing.

And initially we do have this cross which again is no good.

It's assuming that this thing is still a default cube which it's not.

It's stretched vertically.

So what we're going to do is we're just going to go to edge selection.