Godot Tutorial -- Static and Procedural 3D Meshes Video Lecture | Godot Game: Learn and Master - Game Development

hello this is my cat game scratch
welcome back to our ongoing Godot
tutorial series today we're gonna
continue looking at 3d specifically
we're going to look at learning static
3d meshes and then creating our own
programmatically there's actually two
ways we can go about creating them
programmatically one is orientated more
towards create once mesh that you
programmatically generate and then don't
really touch again and then the other
one is more along the minds of opengl
1.1 immediate mode style coding if
you're familiar with that if you're not
don't worry about it but the idea behind
it is basically a dynamic mesh that
changes pretty much every frame or every
few frames or quite a bit it's
performance optimized for a changing
mesh so let's jump right on it and I'm
gonna create a new file up here called
static 3d YouTube and create as you see
I've been working with 3d a little bit
lately but this is the guy we want so
let's fire up Godot let's make sure that
I'm running in the right version here
and I am alright perfect so to
traditional start we've got to create
our blank scene we'll put a node at the
base and as we have seen many many times
save our scene I'll use the default name
and then we'll set it as the active
scene skin again if you don't know this
I assume you've watched the previous
tutorials or you already understand
what's covered so if I do something that
you do not understand
be sure to check a previous tutorial I
guess I should stop and mention quickly
there's a text version of this tutorial
available on game from scratch comm it's
already up and running it's part 15
called static and programmatic 3d meshes
I will link it in the comments below
yeah that's about it so here we go so
first things first we're really going to
need a 3d mesh to work with now for
static meshes we're gonna use the obj
format it was created by wavefront a
small history lesson here wavefront used
to be I dunno basic they were yeah I
believe they were a trauma based company
which is cool cuz I'm in Toronto but way
back in there the pre ages of history
you had a bunch of preeminent 3d
companies there was a leus there was
wavefront and then a bunch
all the ones uh discreet was kind of
up-and-coming but not really a thing yet
they ultimately became Auto um they were
awfully bought by AutoCAD and turned
into 3d Studios max which now owns
everything there was Softimage at the
time etc but way way way back there was
a company called wavefront and their
file format was obj and ultimately it's
been carried on and carried over because
the obj format is really really simple
to work with so it's also not a very
advanced format a lot of things like
multi texturing advanced animations that
are not supported but it is often used
for simple static 3d meshes which is
exactly what going to work with today so
we're going to go ahead and create one
I've actually created already but I'll
show you the process it's just a
textured box from blender so let's fire
up a copy of blender use whatever 3d
program you wish
like I said they pretty much all export
to obj format but here we are typical
cube switch into edit mode mesh let's do
a smart unwrap on this guy which creates
a very crappy UV layout but it's a very
crappy simple UV layout so now we want
to go ahead create a texture on it
texture type is image great new make it
a color grid like so we will call this
guy my texture or whatever you wish to
call it and okay so now let's split my
view over here go down to UV Evan
cheddar now I assume if you've got no
inch no prior experience with blender I
know what I'm doing is way beyond what
you're capable of or what you understand
if you want to learn more about blender
it's not as scary as people make it out
to be I've actually done two full
tutorial sets on working with blender
one is a video series about five hours
in life that shows you the various
aspects and the other one is a text
series about 24 parts in life that shows
you how to actually create game assets
with the 0 previous experience so
obviously I'm not going to touch on
blender too much but it's pretty much
all we want so we got our shape or
texture map our texture map is applied
so our texture mapping and our texture
here last thing you want to do is save
your image externally because it's
actually gonna be a two-step process
when we get into
dealing with the gadot side of things
and then finally just want to come down
here and go file export and you want to
export it as an object file so here you
can see is wavefront even though that
that company name hasn't made any sense
for about 10 to 15 years that's still
what it's called
so you want to export it as an obj
format when you click this you go down
here on the Left you'll see there's a
number of options for how to export it
the important one is probably up you
want the up Y up to be the up
orientation which blender is not however
over just default is that Y is up and
godot's default is y is up so you don't
have to change anything from the default
here but just make sure that the up
Vector is in fact Y and you're also
gonna want to make sure that you V's are
written out so that's your texturing
details and material groups I think are
gonna be pointless because we're gonna
add the texture after the fact and just
go ahead and save this somewhere by some
name it really doesn't matter we're just
make sure that it's available so I've
already done this I'm gonna exit out now
what you do is once you've got your obj
file and your texture available go up
here to import and what you want to
bring is a 3d mesh so 3d scene is
something we'll use a little bit later
on that's for a more complex or animated
scene that we're gonna bring in a colada
for Matt had seen 3d scene animation and
all honest he doesn't seem to do
anything and the 3d mesh is specifically
for static meshes or obj meshes so first
thing you do is pick your bring in your
source - located on my desktop right
about there
see cubed obj and ya
and then finally pick where you want it
to go of course you could create a
folder models or whatever but I'll go
over the root because I'm lazy like that
and you've got a couple of sections the
settings for what you can configure not
really all that many tangents and
normals Mazal leave those on normals is
the direction your face is facing flip
faces this is only something the you're
basically changing the direction so if
you want your if you created a model and
you wanted to be inside out you would
set that to true smooth shading if you
use smooth shading in your your modeling
to program then you would click this on
to bring in to have the smoothing that
you've applied but order a cube there's
no smoothing so finally do
settings are pretty much set for what we
want to do just go ahead and import so
now we have a new mash now I'm gonna go
ahead and bring in a 2d texture as well
this is gonna be our texture map that's
gonna go on top and that is also on my
desktop and I called it cube texture
this is that color grid we created
earlier so obviously is whatever texture
map you are bringing in once again I'll
just gonna throw that at the root thanks
oh and there's a number of settings you
can set here as well
default should be good for you on almost
every case so just go ahead import it
will be compressed for you iWeb P I
think it's the standard that they use so
we now have our texture and our model
available let's go ahead and actually
use them now what we want to do is
create a mesh instance you can have
multiple mesh instances for the same 3d
model so what we want is mesh instance
this guy right here now you'll notice
was also a multi mesh instance now a
multi machine instance is just like a
mesh instance except for when you have a
whole lot of the exact same 3d model and
they're relatively close together so
it's an optimization trick so if you
have say a level where the wall was the
exact same mesh and you had 30 or 50 or
100 of them on-screen you could use a
multi mesh to store all of the different
instances and what it does is basically
batches them all together into a single
call performs a lot better but it's a
very specific use case so if you have a
whole bunch of instances of the same
model close together use a multi mesh
for that but they all have to be the
same and they have to be close together
now if they're really far apart this
could actually be a bad performance
optimization so but this is do it after
the fact when you run into these
situations for most cases you'll
probably just want to mesh instance
otherwise they perform very very similar
so we brought it on a machine instance
there's no mess attached to it yet so
just come on down here and go to mesh
and we'll go to load and we'll use the
mesh that we brought it and tada all
right so we have our 3d model now is in
our world yeehaw
now what we want to go ahead and do is
put that texture on it and that is once
again over here in the inspector
you got your material ride right over
ride right here and what we do flip that
down you got two choice you got shader
material
which is exactly what it sounds you can
set a GLSL shader a segment in vertex
shader to work on your surface but in
this case we actually want to go to the
fixed material it's called fixed picture
because it's a fixed pipeline material
so go ahead and add one and then we'll
edit it okay so here we are inside of
the fixed material no there's a number
of settings already kind of it's it's
sort of like a shader that's been
pre-configured for us for using textures
and there's a bunch of things we can set
turn the Alpha on and off etc we can set
the diffuse which is basically your
color channel specular which is how it
responds to light and the Misses
emission which is how it actually gives
off light so this is a three color
values you can apply to each material
but we also want to do is actually flip
down to the texture section and you see
there's a bunch of different textures
you can apply as well so you can do a
glow texture normal texture normal throm
doing shape depth on the surface that
isn't actually there detailed texture
which I believe it would also be called
a deckle elsewhere etc so there's a
bunch of textures you can apply but
we're gonna go ahead and use diffuse
let's go ahead and load and then just
pick the cube texture we used earlier
and tada
so it automatically picked up the UV set
that we created when we were working in
blender before so now we have our
textured static mesh in our world and to
go ahead and show you this actually
working let's go back to our scene and
fill out our scene so it actually works
in 3d so once again from the last
setting you know you need to create a
camera and you need to add some lighting
to the scene so let's just add a like
and add a big-ass directional light like
this guy bring it up bring it up bring
it up bring it up yeah let's rotate it
down a little bit so it's facing us so
and let's turn off the default lights
there you go so we now have a lit scene
where's my camera there's my camera
let's move it - I don't know which
direction it yeah there we go let's see
how that looks perfect now let's go
ahead and run that and tada we now have
our 3d object in the world all working
so that is loading and creating a static
textured mesh
nothing that difficult obviously you can
run into a little bit more complications
when you start using functionality that
may not export like I'm using a simple
cube with a single texture attached
obviously when you start getting into
more complex things expect things to be
a little trickier but for the most part
that is the process now let's go ahead
and look at programmatic measures this
is also probably the more common word to
be using there is procedural Misha's
that is basically a mesh that is created
or modified using code well go ahead
we'll just delete out our mesh instance
here so this is this guy it's going
bye-bye see ya all right so now we're
going to create a mesh specifically for
us to create it on the fly using code
and we're gonna do is go in and we will
create an instance of immediate geometry
and now we need to add some code what
did i do I can't put the code right in
it like so so let's add a new class here
go with the incredible name of did you
do to it my mesh Gd all right
so create that guy so welcome to some
new code and all we're gonna do very
simple logic on this guy when it's ready
we're just gonna go ahead and create it
now I'm not gonna tell you too much
about primitive GL construction this is
basically a small layer over top of
OpenGL and it's kind of the
old-fashioned way of working with OpenGL
so if you've done some open GL
programming what I'm about to do is
gonna look very very immediately obvious
to you if you haven't true the matter is
dynamic meshes aren't for everybody a
lot of people aren't gonna actually I
have to go ahead and create these things
it's only if you need to go below the
functionality that it's actually
provided I could do that you're actually
gonna go down this road so if you want
to learn more about building a mesh like
what UV czar how vortexes go together
what a triangle list is versus a line
list versus a fan stripe versus all
those way beyond what I can talk about
here but any OpenGL guide or materials
will walk you through that so I won't so
first things first I'm gonna use myself
because I like doing that so we're gonna
tell it we're gonna
start doing some drawing calls here
virtus structure I believe is what V s
stands for and here we are actually
telling it what type of primitive we're
creating here and we're going to create
a triangle and there's no texture for
said triangle okay so that's our first
line next up we're actually gonna build
so all we're doing here is we're
building a triangle oriented about the
origin so we're gonna create three
vertices and that's it so first thing
we'll add our first vertex right there
that's a vector three and it is at 0 2
and 0 now units are absolutely arbitrary
you can be 2 meters 2 hectares 2
millimeters to micrometers 2 parsecs
even though I think a parsec is a unit
of time it could be whatever you want it
to be just be consistent about it
there's no logic in what I'm doing here
so the 2 is just 2 just so make sure
that your corresponding lighting units
and camera etcetera all kind of work
with it or fudge it by hand it doesn't
really matter it does make sense to pick
meters or feet or millimeters or
whatever makes the most sense to your
game I guess depending on the scope of
your actual game itself but all right so
that is one unit one vertex down the
order that you draw is important I think
the default is a clockwise and so draw
your vertex is in the clockwise order
that you would like the the shape to be
created so I did the left now I'm gonna
do the top and then the right of the
points of our triangle so this one is
going to be at oh wait no I didn't I did
the first one was the top so now we're
doing them right it's 2 2 X 0 0 and then
finally our last vertex tooltip you're
annoying the out of me oh sorry
didn't mean to swear if you're from
Godot please make your tooltips less
annoying and dot ok so basically all
we've done here is we said we're gonna
do some drawing and it's a type it's a
triangle over creating we created three
vertexes as part of our structure and
then now that we're done and so when
this is instance and when it's ready it
will just basically go ahead and draw
trying
now let's see if it worked tada
so that is for creating dynamic geometry
pretty simple not that much work now
there's not again there's not a lot of
reasons why you'd have to create dynamic
unless you are working on a voxel based
game procedural game another common use
is a train engine those kind of things
definitely useful if they are but it's
if you're wondering well why don't I
just use meshes and then later on Colada
meshes or animated missions or scenes as
they're called why would I just use
those well in most cases you would so if
you don't want to be doing programmatic
generation you don't have to but if you
do here is one way of doing it and
that's immediate job and the word
immediate is key there that's for
geography that is going to change a lot
so if this is not going to change every
frame there is a better way of going
about doing it and I will show you that
now so this is again for geography the
geometry that is going to change
constantly as the so as the game goes
it's going to be updated that's what
it's optimized for and it provides like
a GL 1.1 style drawing API so if you
want to learn more about this way of
doing things go back and look at
documentation for GL OpenGL one-ish 1.1
and you will see lots of examples and
you'll be able to guess exactly how this
kind of stuff works going forward
so again immediate geometry classes are
meant for geometry that is going to
change a lot now in the case that your
geometry is going to be basically
created and then forgotten about then we
were going to do with the mesh instance
again and you think it missions wasn't
that exactly what we just used for the
3d model and that's exactly what we just
used for the 3d model the only
difference is instead of getting it from
a 3d mesh that we used over here we're
actually going to go ahead and create
one and we're gonna create it using
something called surface tool which is
like just a helper class for making mesh
files so let's go ahead add a new node
and it's a mesh instance like you and
now we're gonna have to add some code to
this sucker so let's go my mesh I forget
what I called the last one so I'll go
with my mesh instance and go ahead and
create that guy
and once again we are going to do
everything in ready and once again we
are going to be creating a triangle but
we are going to do it in a much more
convoluted way but if you were working
on a more complex shape something like a
terrain engine and you wanted to have
textures or multi textures or vertex
coloring or more advanced details
especially because it's not going to
change a lot because if you're there's
going to change a lot use the immediate
geometry but if it is so one of those
things like create one and forget about
or create once an update occasionally
this is the way you go about it so as I
said earlier we're gonna go ahead and
use something called surface tool so
let's create one surface to old dot new
so we have our surface tool we are going
to need a mesh so we're creating a new
mesh instead of loading one dynamically
and we're also going to go ahead and do
a material in this case and it is a
fixed material do one of those all right
so first thing let's apply our material
dot set or a mid-term and this is
passing in a value to it we're gonna
pass into the diffuse color on it oh I
did it this way but alright so basically
we're creating a red material so it's a
material dot per ram diffuse now as I
said earlier diffuses basically the
color Channel normally where your
texture would go but it's also where
your color information is stored and
passing a color value of red bull red
miso so basically create a material and
make it red
now you can also create the material
programmatically we'll see that in a few
minutes okay so that'll be very very
cool something else to show you so if
this looks a little ugly to you don't
worry there is a very cool option and it
does show some of the power of Godot so
we'll get to that in a second it's a
great example of how it works so in the
meantime surf tool dot set material
material like so so think of a surface
tool as a mesh to be
so apply the material on top and now
your interface is going to look awfully
similar to what we had before so V s dot
perimeter here are your different types
way beyond what I'm gonna cover most
times you'll be doing probably and if
you're doing geometry it'll be a
triangle triangle stripper or triangle
fan normally triangles unless it's
optimized and they're probably a strip
the other ones are specialized again
beyond the scope of what we're talking
about here
so there's first things first we went
ahead and set our draw to start now the
first thing we're going to do is create
a UV point for our vertex the way I did
this was let's see left left bottom
vertice top middle of vertice right
bottom vertices so once again the order
is important that you draw these things
so let's set our UV now UV coordinate is
a value from 0 to 1 that indicates a
position in 2d now we're dealing with a
triangle here so obviously the
coordinates are a little bit off but
basically the bottom left corner which
coincides nicely with our first vertex
is at the position 0 0 so let's add that
UV in see I need a vector vector 2 and
that's at 0 0 so so that's our first UV
and now we'll go ahead and set a vertex
there as well
vertex and that's a vector or 3 instead
and we'll make this guy at negative 10
so negative 10 X 10 Y and there's no
depth here so all of our Z values are
going to be the 0 so first vertex now
that this is the top middle vertex so in
that case we need to add our UV again
but add UV in this case since we are
halfway across the screen or are halfway
across our theoretical square that's
gonna draw on top of our texturing or
coloring on top of our shape we get by
we going half way like so now we're
the top so we worth one so those are
coordinates as I think of a virtual
square over top of your shape and this
is identifying where each thing is in
that positioning so 0 0 is the bottom
left that shape and 1 1 is the top right
so 0.5 and 1 is halfway across the top
surf tool dot add vertex victor 3 so
this is very important if you are going
to be applying a texture because the
texture needs to know where stuff is
more or less and that's what the UV
coordinates is providing and then
finally surf tool dot ad so the final
vertex first it's UV so that will be at
C that's 1 in 0 like so once again the
code is all in the linked example on the
bottom in the comments if you want so
don't worry too much if you're not
typing so slow you can keep up no
problem but if you want to copy and
paste the code it's available on the
example vertex vector 3
so why did I change from 2 to 10 for my
coordinates you may be asking no
particular reason just to show you what
size change difference does two things
that's about it so I could have gotten
with two twos and twos again so we're
gonna have to zoom our camera back a
little bit to actually see this triangle
that it does show you the effect of
these coordinates on positioning in
space which I'll show you in a second so
now that we've done we've created our
shape now I'm gonna make two calls one
of these probably is not required I'm
not entirely certain but both are good
to call I think we've one is an
optimization but first off generate
normals a normal is the direction of
faces facing which you're ordering made
it very easy so that generates our
normals on our mesh and next up is
create the index that is the the
offsetting of each vertex within the
data structure which may not be required
but oh well especially on a more complex
measure definitely don't want to make
that call in this example I'm not sure
if you have to or not now we're finally
done this is basically commit should be
called build and surf will should
probably called
mesh builder so if you think of it sort
of cool as mesh builder and you think of
commit as build this makes a lot more
sense so pretty much we're now saying
all right this mesh that we've been
working on let's go ahead and build it
now and we are going to build it to our
mesh value that we created earlier now
this is an extra step you do not
actually have to create this mesh
variable because our mesh instance
actually has one but I find that the
though grossly uh not to do I find it
actually reads a bit better but do be
aware you could have worked directly
with self that set mesh or self-taught
get mesh for the commit right here but I
find this a bit cleaner to read so
anyway so there we go we just did
basically the same thing we did last
time
except for we set up you Ving
information so we can actually draw on
the surface and we made it red and let's
go ahead and run that find out if I did
any typos I did all right so first off
that's a vector two not a vector and try
that again there we go
big red triangle now again I changed
from two the value of 2 and our vector 3
to the value of 10 so obviously we're a
lot closer to it so to fix that go back
to your 3d scene scene grab your camera
turn off preview mode grab your camera
like so let's zoom it back a bit now
preview is not gonna work at all for
your mesh instance because your code
actually has to run for this to make
sense which is a little unfortunate
however set of V so you don't see the
mesh obviously until we go ahead and run
it let's go ahead and run that and red
triangle I should go yeah we moved back
slightly more should be framed and there
okay so there is our triangle now let me
show you something very very very
powerful about Goodell this is a really
cool feature and let's flip on back to
our guy over here
do I have to change here is the
allocation okay so let's go back into
our code like so and what we want to do
is instead of making this material here
read let's make it so that we can set it
very easily so let's just get that line
out of there so we've created a material
and we're going to create a material I'm
getting rid of that line too we're not
going to set it to red we're gonna
create this so we're gonna create this
material instead of being a local inside
of ready we're actually gonna make it a
member variable of our extended mesh
instance here so what we want is then
var material equals no so we're creating
an empty material here now watch this
part this is very powerful and can be
done for just about any kind of custom
class or custom node you create and you
want to expose it to the editor so I'm
just gonna go ahead and say I'm gonna
export this variable and it's type is
fixed material so and I don't know why I
threw a comment beginning in that line
because that was just weird so what I've
just done here is I've said our class
here of mesh instance extending
emissions since I guess I should have
named it a little bit better has a
member variable called material that
we're gonna export give it a default
value of null okay so we no longer have
it set here and it is no longer red so
go ahead and run this code and there's
no material at all okay so we have our
normal triangle and that value is not
being set however now that we have set
this export here let's go back to the
editor and we'll select our mesh
instance here now go over here to the
inspector and you'll see there's now a
script variable section and it has a
value materials you can put just about
any you can export so any value you want
and if there's an editor for it it will
automatically come up so now we can come
in here and go okay let's apply your
material to our guy
and we can even go so far as to go no
but it's the same scene I should still
have my texture from before so go ahead
and load it texture but this is the same
scene with my texture gun let's bring a
new texture in import 2d texture
important oh no I'm not doing that I'm
not loading in texted duh that was
stupid
edit there we go now let's go down to
defuse and load our texture and pick
cube texture run ah so you can easily
expose your textures out your you can
basically set any dynamic value you want
that's programmable and have it exposed
to the interface just simply by adding
that export call so that is pretty
powerful stuff so if you do have your
own classes but you still want to
control and configure them in the editor
you can't you just come on back in once
again and you insert it using an export
call like that
pretty powerful stuff so what I'm going
to cover for today so what we saw up
today quick quick recap first off we
used a mesh instance what we loaded
using the import tool here and brought
in an obj file that we created in
blender called a using the 3d mesh
importer now it brought it in in the UV
coordinates but there's no texture
attached so we also brought it in as a
2d texture that was then pasted on top
after that we went ahead and looked at
the two ways of doing a programming
magical creation the first one we looked
at was immediate geometry immediate
geometry is designed for geometry that
changes very very commonly after that we
then looked at creating our own mesh
instance just like the earlier one we
did but instead we created one from
scratch using surface tool again I
created an extra mesh here so be aware
that you don't have to do that yourself
but it is basically creating a mesh
on-the-fly dynamic and beyond UV there's
a bunch of other things you can set so
let me just show you very quickly and
surf all that sort of tool so bones
color normal smoothing groups tangent u
v 1 UV 2 vertices wait for bones mmm
let's see what else is important here ta
da da da da so there's a bunch more that
you can figure than just the vertex that
we did or you can go in there basically
add bones in that you could animate them
after the fact you can basically create
any kind of 3d geometry dynamically that
you want and that was how very very cool
stuff I could also switch this over to a
shader material we could then
so I mean just do that quick I'm gonna
cover shader materials at a later point
in time but so now I come on back to our
mesh instance material and let's go
you shader material well edit that
sucker and then what you can do is come
in here and go new shader and that
sucker and you can create a vertex
fragment shader using code right here
which I'm not going to even bother
because it's way beyond the scope of
what I want to do but as you saw it is
not easily exposed out to your code that
export line is very very powerful
functionality of what could oh and you
can do so that's three ways of dealing
with static meshes now next up again
we're already over half an hour here so
I I split this into another part so 3d
is sprawling a little bit but it's a
pretty advanced topic but in the next
one we're actually look at bringing in a
Claddagh file which is a steam we're
gonna export with animations etc
textures applied all that so this is
where you would bring in your your
character mesh is your dynamic stuff in
your scene etc now keep in mind what we
looked at today the static meshes is
lightweight compared to that so it will
this will use up more resources use up
more memory more CPU all that stuff so
if you don't need anything more than a
static mesh don't use anything more than
a static mesh so stay tuned for that
next part I hope you enjoyed this part
once again a bit of a plug here if you
do enjoy these tutorials etc and you
want to see they mean we keep creating
them well I'll keep your regardless but
I do have a patron fund running
everything helps a great deal so if you
like it'll be linked to below to all
your support is definitely appreciated
so I hope you enjoyed that stay tuned
for the next part see you soon bye