Transfer HIGH POLY details to LOW POLY object in Blender

>> Can you tell which one of
these rocks is low-poly model?

Today you will learn how to turn your
high-poly model with all the fancy details

into a low poly model but to
keep all the details there.

So let's do it.

Remember the previous episode where you learned
how to create this really cool rock or stone

out of a cube or any other mesh that you like?

Well that's cool.

But if you go to edit you can see that this
is really dense mesh, really high-poly mesh.

And if you go right here and turn on
statistics you can see that we have

around 210 [inaudible] and around 30,000 faces.

It's an enormous number.

And if we make a copy of this rock and make some
really cool scene, we'll have millions of faces

and blender can hiccup, get frozen
etc., and you will be stressful

and maybe blender will break eventually etc.
So we need to lower the amount of polygons

but to maintain the same
details that we have right here.

So how to do that?

Really simple.

First of all, I want to rename
this to rock underscore high,

like this is high amount of polygon.

And then shift d to make a copy; press escape
to leave it at the exactly same position.

This is really important.

They need to overlap.

And I will rename this to
rock [typing] low obviously.

And now let's turn this from
high amount of polygons to low.

So there are several ways how you can do it.

I will show you two.

We can add decimate modifier
and lower the ratio here.

So for example 0.002.

Let's see; press enter, and
we will go to 915 faces.

This is decent and we can work with this.

Amazing. So that's one way how you could do it.

Another way is to go right here and go to
remesh, and we can remesh using voxels.

And the higher number here the
lower amount of faces we'll have.

So we'll go, for example, 0.2, let's see.

And this will bring up -yeah, we need
to press voxel remesh, obviously.

And this will bring us to 638 face.

And this is decent; this
is what we can work with.

And from 230 000 faces all
the way to 638, amazing.

So this is a huge difference.

Now in order to transfer all these details

to this low-poly version
first we need to unwrap this.

Unwrapping means that imagine that you have
a really cool cube cardboard box and you need

to open it completely; unwrap it; and then you
can place some really cool, nice, shiny paper,

some textures whatever on that unwrapped part;
you can wrap it back; and you have really nice

like a gift box something like that.

So we need to unwrap this rock in order to
paste some maps and some textures back on.

So this is really simple.

We can go to UV editing here,
and just press a to select all.

And currently this is empty.

We can go to UV here, or just press u on a
keyboard, and we can use smart UV project.

For this project this is really enough.

I will go with margins a little bit
higher so that I don't have overlapping.

And this is like we use the scissors and
cut out the certain parts of the rock

and just place it flat on the surface.

So this is it.

And now that we have that,
we can go back to the layout.

Remember you need to have
low-poly version unwrapped.

High poly you don't need to worry about.

So now let's go to -- let's
play the screen here, okay.

And here I will go from 3d viewport to
shading editor and to hide this menu,

and create new material for this rock.

Perfect. Now what we need, we need two
nodes, shift A, and we need image texture.

Okay. One node there -- and shift
A. And we need normal map node

because we will bake a normal map.

We will use all the details from the high-poly
version and bake it to a normal map and apply it

to low-poly version, and then
we will have free details.

That means that we will render
this for free in manner

of calculation etc. It's basically having
a fake details there that will look real.

So you'll see.

So normal to normal and color to color.

Okay. Perfect.

Now go here and create a new map.

I will name it rock underscore normal.

Okay. And I will go here and select
both of these and just multiply by four.

Because I want to go from 1k to 4k resolution,

the higher resolution have the more
details you can make and that's cool.

And we can leave everything as it is.

Press okay and switch color space
for SRG -- from SRGN to non-color.

That's important.

So you want to have non-color here.

Perfect. And now we can add
optional modifier if you want.

For some examples this is really useful.

Here it's not too much but I want to show you
that you can try that shrink wrap modifier

to wrap vertices from low-poly
around high-poly version,

but because they are pretty much the
same it will not have any difference.

But let's show the high-poly version.

Go to the shrink wrap and just
select the target rock high.

That's it.

You're done.

You can apply it if you want and that's it.

You're completely done.

Now we want to go to the render tab here.

Go from [inaudible] to cycles;
this is important.

And you can go with CPU or GPU, whatever.

If you have a nice GPU card you can do that .

And basically we can have here
for the render 128 samples.

It doesn't need to have too much samples
because we are now just rendering geometry.

But we want to go to the bake here
because we want to bake normal.

And from bake type, from combined, we
want to switch to normal; that's it.

Leave this as it is.

Bake from multi-resolution.

There is another way how you
can do exactly the same thing.

Bake from multi-resolution, but
I will show you a different way.

So let's go select it to active,
and now we need to select this one

and control and select low version.

So select high version, high-poly version,
control and select low-poly version.

This is really important
in order for this to work.

And we can set the cage.

Cage is basically -- let me
show you really quickly here.

If you select the low-poly version, make a
copy shift D, and just -- let's hide this --

and just make it big enough to
cover the high-poly version.

So this is the cage inside that cage.

It will be baked.

The maps will be baked.

So this is useful sometimes, but because we
have this only the rock, we can skip this .

And instead of that - I made so many copies.

And instead of that, I can go
with extrusion, so 0.5 meters.

Same like cage, making extrusion.

So this is it.

And before we bake this, I want
to go to the high-poly version,

and right click our W and shade smooth.

Also to low-poly version, shade
smooth, in order to make maps better.

So if we don't do the shade smooth,
the maps will have this crazy geometry.

So shade smooth is important.

And make sure that here the --
the auto smooth is not checked.

You don't want that because
you will have all these things.

So not checked on both versions .

See not checked.

Perfect. And then remember,
select the high version, control,

and click to select the low-poly version.

Go here to the bake.

Everything is set.

Extrusion is set.

Selected [inaudible].

Just click bake.

And now as you can see right here, the
blender is started baking this and in a matter

of few moments or minutes, depends of your
specs of computer, and of course the resolution

of the normal map that you set
we will have normal map baked.

I will pause this for a moment
and come back soon.

And the map is baked, and in order to see
it we can go for example to a shading tab.

And here we have an image viewer
node and we can go right here

and choose a rock underscore normal.

And this is how our normal map looks.

Perfect. It's already applied, so we
can hide the rock high and this is it.

This is our low-poly version
with all the details.

And in order to see this better,
I can just change the material.

So let's make it darker, for example.

Let's reduce the roughness a little bit,

and maybe add metallic just
to see the details better.

See, this is amazing.

And if you go to the render here, everything
is dark, so I will go with some HDRI map.

So this looks amazing.

And in order to compare it
with high-poly version - see.

So let's change the material here.

Add -- I want to add the same material, but I
need to make a copy, and I need to delete this

because this doesn't need
to have all these things.

So let's move it.

Let's go to the top view and move it.

Show this one.

Move it here.

So we have one beside other.

And can you tell the difference which
one is high-poly, which one is low-poly?

Let me just hide this background.

So this is nice.

And if we go back to the layout
-- let me show you a trick.

You can still see this as a low-poly
with -- if I hide this -- with 638 faces.

But if you go to the shading here,
you will see the full resolution,

and if you go to the render
here, you will see everything.

So, as you can see, low-poly vs
high-poly but with transfer details.

So basically if I just rotate like
this, can you say which is which?

I have no idea.

They look amazing, both of them.

So this is it.

Another version to do it with the
multi-resolution is, again, really similar.

If you want, I can show you really quickly now.

Okay. If you insist, I will
show it really quickly.

So basically, it's the same.

I will make a copy of this, and go right here.

And this is how it looks.

So we went to this part, and
instead of -- so we have the map.

This is rock underscore normal, number two.

So we created a new map.

Everything is cool.

Non-color mode.

So everything is exactly the same like
previous way, but now we need to go

to multi-resolution tab here, add not
modifiers, and add a multi-resolution here,

and then add the shrink wrap modifier.

You need to do that this in this
order, and choose here the rock high.

Perfect. And this is not good because
you can see the rock high is not

in the position, so make sure to align it.

I will bring it back to where it was.

So now I can hide it, and go back to this one.

Choose the rock high.

Perfect. And just with the multi-resolution,
you can subdivide it until you think it's cool.

So I can go with four or maybe five levels.

Yeah. Five is better.

And now this looks like the
original high-resolution version.

But instead of level three,
four, five, we will press zero.

And we want to apply a shrink wrap.

So shrink wrap, apply.

That's it we only want to have a multi-res
modifier here with these settings.

And go right here.

Go back to bake.

And instead of selected to active,
go and set bake to multi-res.

Make sure that this image texture is
selected, if not selected, and just click bake.

And this time we don't need to
select any of these together.

This can be like that, and wait for a few
moments in order to -- this normal map be baked.

And I will show you the result.

Okay. So let's go here to
the shading, and this is it.

We have really nice result.

If we disconnect this, we'll
have not so good result.

But back with this we will have all the
details back also to the render tab here.

Again, all the details are here
and this is exactly what we want.

If we want to compare it with this
one, again, here's the same --

maybe here is a little bit better visible.

So this is high-poly.

This is low-poly.

And now what you can do is to go to the
modifiers here and just apply this multi-res.

You don't need it anymore.

And this is it.

And you can see we have 638 faces.

We can just make a copy of this,
as many as we want for our scene.

We can make some really cool scene.

I'm just randomly making this.

But our viewport we won't
freeze because we have just 630,

380 faces this is really low
amount of faces for this.

And basically we have all the details.

And if we made this amount of copies from the
high-poly version, we'll have millions of faces,

and it will be totally different story.

But this is really, really
cool and really handy to know.

And in a lot of situations you can save your
day by transferring data details practically

from high-poly to low-poly version with normal
maps and make game-ready models like that.

All right guys.

Let me know down there in the comments
what you think about these episodes.

And just practice and enjoy
making things in Blender.

See you in my next fun episode.

Bye, bye.