Animation advanced 3D Character Mapping
Hello
This is Seunghan Yoon for the Maya modeling class
The shading process almost entirely utilizes textures
Texture creation in the animation industry
mainly used Photoshop in the past, but these days
along with the use of high-quality texture sales sites
a powerful texture creation program,
Substance Painter became the industry standard
Substance Painter is different from Photoshop
You can work directly on the 3D display
and various materials are provided
And color, roughness, and normal texture
production and creation are done all at once
Not only in the animation industry
but also in many video production companies, including games,
it is one of the favorites
However, this video is about learning about Maya's functions
so I'll just mention it here
In this course, we will learn about the basic shaders of Redshift
with textures available on free sites
The learning objectives for this lesson are UV theorem and
expressing various textures using textures
The learning content is
First, efficiently spread and organize UVs
Second, expressing textures through shaders
Efficiently deploy and organize UVs
Shading work is the process of creating a gray polygonal mass
and adding more realistic colors and textures
We mainly use textures, but
depending on the style of the animation, instead of textures,
there are many cases where work is done only with coloring
We are going to do shading using color and texture
Before we get into shading
First, you need to unfold the UV of the model
No special techniques are required to unfold UV
I think you just need to be aware of a few things
For reference, this lecture is conducted on the assumption
that you are familiar with the basic functions of Maya
Please note that the lecture will proceed
beyond basic functions, focusing on work tips
First is things to keep in mind when working with UV
When cutting UV, we will cut mainly the invisible parts
The basic objects provided in Maya are
originally created with the UV spread out from the beginning
There is something here that you need to pay close attention to
UV and vertex correspond to each other, but
It's not necessarily the case that the UVs match the number of vertices
If you look here
If you select one vertex,
On a 3D display, there is only one vertex
If you look at this in the UV editor window,
The UV point are two of them
This UV is
the part that is separated during the unfolding process of the 3D objects
Just like a globe and a world map
The edge of this separate part
The edge of this separated part is called a seam
This, this
Let's try applying a texture here
Search for Lambert in Maya in Hyper Shaders
Load the checker file
To put it simply, the checker file
There are a series of rectangular shapes like this
It refers to a file that is literally made in the shape of a checker
in the form of numbers or squares
to check for sagging or interlocking parts of the face
If you look at the seam part
The textures of the seam do not mesh with each other
You can see that they are connected with completely different textures
This scene is a very noticeable part of the actual video
So it must be corrected
If possible, cut in a place where the UV seams are not visible
This will reduce the chances of these parts being noticeable
For example, when making a costume, there are cases like this
Here are two clothes
There is little difference between these
I just left a sewing mark on the fabric on the right
There are no sewing marks on the clothes on the left
On the right one, I modeled the sewing traces
If you check with the UV editor
UV is divided into two sides, front and back
The UV parts are separated from each other
So, if you check it on a 3D display,
The places where the fabrics interlock look awkward
It feels like the picture is cut off
In this case, the solution is to model the sewing line
If you make the invisible edge part of the modeling into a seam,
Modeling is also expressed in more detail
and it will also look more intricate
And a lot of the awkward parts will disappear
The seam position of all modeling must preferably be on
The back side rather than the front side, the bottom side rather than the top side
and on the hidden edges rather than the exposed parts
Those are the preferred placements
The second is minimizing UV incision
There is some part that is similar to the previous content, but
The more cut surfaces there are, the more likely it is
that the part will be visible
Unfolding UV means making 3D into 2D
In this process, distortion inevitably occurs
When distortion occurs, the resolution of the texture of that part
and the appearance is significantly impacted
Therefore you need to cut the UV in the right place
A place like this that catches the eye
Just because it's a joint
doesn't mean that the texture must be cut there
In the middle or somewhere visible like this
If you cut it without any reason
You'll see a lot of misaligned textures
Mainly in the case of characters or costumes
Make an incision at the large joint
Incisions are made on the neck, shoulders, waist, hands, feet, etc
Third, minimize empty space in the UV window
When each texture is rendered
This may be the reason for increasing the time
To optimize assets as much as possible
It should be created with minimal UV shell space and empty space
All the parts I'm selecting now are UV shells
But these empty spaces next to UV
It's wasted space
If space is running out by a small margin
Reduce the size of some UV shells as a little trick
However, even if you reduce it,
is must be where it is not as noticeable
For example, inside the mouth, inside clothes
or parts like the soles of shoes are some examples
If you can secure more space
It is also a good idea to straighten and spread the UV shell
If you look at the sleeve part around the neck,
In fact, if you unfold this as it is,
This kind of curve shape comes out
These parts, now, we have a lot of space left
so we can place it like this
but if there is no space
It would be better to straighten this part and place it
However, straightening it requires a bit of work
In my case, I often use straight shell commands
When you can't get it straight the first time
It will be easier to split the work into several parts
Third, directionality in 3D displays
and the directions in the UV editor is better when aligned to each other
This is not mandatory though
This will make working with textures a bit easier
Let me explain what it means
Shoulders are facing upward
The left shoulder is also facing upwards
It is recommended to place them facing the same direction
in the UV shells as well
The shell part of the body also has the neck part facing upwards
The part on the back also has the neck facing upwards
Then, the direction of the shell in the UV editor
is better with them face the same direction
This directionality must be placed
while considering the pattern of the texture
If the same type of UV shells are in different directions,
There may be one more extra task
For example, let's say you have one arm positioned horizontally
So what does it look like when actually rendered?
The pattern of this texture is vertical
The texture pattern on the arm is also vertical
But the arm side that was placed horizontally earlier
The textures are connected in a horizontal shape
If it becomes like this, with Photoshop or Substance Painter
I need to work on the texture again
Please keep the three points mentioned in mind:
while working on UV
and there will be fewer things you'll have to re-edit later
So now let's start modeling
Let's try UV work
The scene you are seeing now
For the part of the ear where it is attached to the head
I cut it separately because I thought it would be severely distorted
When cutting, it is important to cut the parts that are not visible to the eye
or mainly around the corners
When you first check the UV, the UV connection is
all messed up
In this case, just go to the UV menu
and shoot Planar or Normal Based Projection
and create the seams one by one
While working on UV
You may find some mistakes
that didn't notice when modeling
In practical situations, in urgent situations,
being passed onto rigging with only polydon modeling done can happen
As the animation progresses, the modeling team
creates textures and merges them just before rendering
It's a bit risky, but it is often used in a hurry
In this case, don't pass it right after modeling
I recommend that you do the UV work and then pass it on
That is because when working with UV, you can spot
parts of the model where there are mistakes
For efficient use of space
I spread the UVs as straight lines as much as possible
There may be some texture distortion, but
I spread it out in a straight line since it is not easily visible
If the modeling is duplicated
Because the vertex numbers are the same
Via Transfer Attribute
You can duplicate UV
The incision was made mainly in the invisible parts
like the armpits, inner legs, soles, etc.
This character doesn't have textures on every parts
but in practice, there may be situations where textures are added later
For example, if a dirty map is added to the body,
Or, there may be cases where doodles or something like that gets included
That's why we recommend that you do
UV in such a meticulous way
Just like a polygon has a front and a back face
UV shell also has front and back
You can check by pressing key 4 in the UV window
If it's marked in red, it's on the back
Just because you can see the back
It's not like there's a huge problem, but
If possible, please spread them all out to the front
When a normal map is applied, if it is applied inverted
That part will come out different from other parts
with contrast can be included
If there is space left, focusing on important parts like
eyes, nose, mouth, face, and hands
you can enlarge them a bit and place them
The face and hands are the areas that the camera captures the most
which makes them very important parts
For texture detail
You can enlarge them only if there is space left
When you think that the UV work has been done to some extent,
Finish by checking using the checker map
Expressing textures through shaders
After finishing UV work
before we get into the shading,
Let me briefly talk about shaders
In the early days, there were separate shaders for each material
Basic shaders, plastics, metals, skins, glass, etc
But these days, with just one shader
we can express many materials
Especially since the introduction of PBR-based rendering systems
There is now a single established standard shader
For reference, PBR stands for Physically Based Rendering
and it is a method of rendering by simulation
of how actual light reflection physically occurs
Simply put, the reflection of light in the real world
is implemented
Back to the topic, not only Redshift
but all renderers, including V-Ray and Arnold,
have one standard shader each
Open the hyper shader
If you look at the redshift shader in the section below,
Here's a glowing material
If you don't see this part
go to Windows - Settings/Preferences - Plug-in Manager
and check if redshift4maya is enabled
If you look at this material,
It says redshift material
As the most used shader,
Let's learn about this shader
Let's take a quick look at this simple image:
We see the visible light of sunlight
to be the color closest to white
In this explanation, we will assume it is white
If we analyze this white light through a prism,
It is divided into several colors
into rainbow colors we commonly know
that is, red, orange, yellow, green, blue, indigo, purple
There is a sun and an object reflecting light
And then there are our eyes that receive that light
Light that contains many colors
will hit the surface of the object
At that moment, light reflects in several different ways
First of all, some of the light is absorbed by the object
One of the things that was trending on the internet
is something called Vantablack
In this case, 99 9% of the light is absorbed
This part alone feels unrealistic and hollow
This is a good example of light absorption
And some of the light is reflected back directly from the surface
This is Reflection
Some of the color received from the sun
reflects as white and enters our eyes
The smoother the surface texture,
the more you can feel the shape of the light source as it is
The rougher the surface, the more blurry the Reflection will feel
By scattering light we can measure the roughness of a surface
with our eyes
This is expressed as glossiness or roughness
It is a very important element in expressing the texture of an object
Looking at the material of Redshift
There is a Reflection item
The color is usually set to white
If it's a normal material, not a metallic material
Most reflect light in a color close to white
If you want to reduce the intensity
You just need to decrease weight
Roughness below literally means the degree of roughness
So the higher the number,
the hazier the reflected light becomes
The lower it gets, the light reflected
will be clearer
There is something here that you should pay attention to
It's a Fresnel Type
Fresnel is the concept that when an object reflects light
Depending on the angle between the observer and the object surface
the reflectivity changes
If you look at the picture
The angle between the line of sight and the normal direction of the object's surface
ranges from 0 to 90 degrees
The left side of the graph is reflectivity
Below is the normal direction of the surface and the angle with the eye
From the perspective of the eyes
When light hits an object and enters the eye
If this angle is 0 degrees, then this 0 degrees is this way
Here, the angle between the eye gaze direction and the object normal direction is
90 degrees which refers to this part here
As you can see, the reflectivity is low at 0 degrees
As you go to 90 degrees, the reflectivity increases rapidly
Just like this image
Almost all objects except metal
increases in a gentle curve like the graph
That is, assuming the shape of a sphere
The edges reflect more brightly
Back to Maya again
In the case of general materials,
it uses Fresnel Type IOR
but for metals, you can see here that we set the Metalness
The IOR of metals is a little different from that of non-metals
As you can see from the graph
Strong reflections were created from the beginning
but then reflectivity drops around here
Then again, the closer it gets to 90 degrees,
You can see it rising rapidly
To express this unusual reflectivity,
Rather than using the general IOR type,
a separate type called Metalness is made and and set up
If the strength of Metalness
is 0, it means it is non-metal
If this is 1, it means it's metal
So what are these medians?
If it's a metal, it's metal, and if it's a nonmetal, it's a nonmetal
You may feel confused
I think of it this way
Let's assume we are painting on pure iron
The paint has the same IOR as the plastic
When you paint it, the paint has a non-metallic feel,
but if you apply it thinly, the metal underneath
will be revealed to some extent
If I paint it again
The feel of the metal remains only slightly
The paint will leave a stronger impression
If you apply one more layer, there will be no metallic feel at all
Only the feel of the paint will remain strong
This item is so expresses the intermediate levels
of metal and non-metal
in a form of a slider
To give the feel of the paint coating being weathered by the ravages of time
and being peeled or worn out in some places
If you use a texture by connecting it here,
You will be able to express that effectively
Back on the path of light reflection, some of the light
Among the sun's wavelengths of red, orange, yellow, green, blue, indigo, and violet
Reflects only a specific part of the wavelength
and some are absorbed
The wavelength of the light reflected at this time determines the color
The color of an object
We think that color itself has its own unique properties
Let's analyze this a little more deeply:
The color of an object is determined by its unique characteristics
It just reflects light of a certain wavelength
We call this Diffuse
You can express the color of an object with diffuse color
Diffuse is also the most important part
used shading
Back in Maya, go to the Diffuse item
You can specify the color here
Sometimes you can even link textures
The Weight value is 1 by default
This is a setting that is not touched much
The roughness below, depending on the roughness of the surface,
changes the feel of the diffuse
It is mainly used to express materials such as velvet
Some of the next light penetrates the surface
and will reflect inside the object
If you magnify an object, you will see that there are a lot of particles
Among them, in the case of the skin of a living creature
It is mostly filled with water
Light penetrates deep into the skin
This light collides with countless particles inside
and comes out of the skin again
We call this Subsurface Scattering
This characteristic is widely used in objects that allow
light to pass through to some extent like living things
Let's take a look in Maya
Subsurface Scattering can be seen in this section
The object on the left has its total amount set to 1
And the object on the right is set to the default value of 0
When we say that the total amount of subsurface scattering is 1
it means that Subsurface Scattering is enabled to the maximum
Let's try rendering
If you look at the rendered result,
You can see the characteristics of subsurface scattering
Because light undergoes multiple scattering movements
It reflects in various directions
Shadows also have blurred boundaries for that reason
It is also expressed by mixing in the color of the object
If you look at this side, compared to the object on the right,
The dark parts are spread out a bit more smoothly
There is a slight color value mixed inside
To better see the shadows
Let's try rendering again
after putting an object on top of this
If you look at the render result again,
The expression of the shadows is a bit more distinct
Because the light is reflected from inside
The shadows are getting lighter
and also give a blurred feeling
In the case of human skin,
Because the composition of the outer and inner surfaces of the skin are different
The colors on the outside and inside also differ
The color of the inner part
You can change the color in this layer
I'll set it to red to make it stand out
Let's try rendering again
The render result is out, but the sampling value is low
which made it come out a little messy
Let's adjust the sampling value and try again
I adjusted the sampling value and re-rendered it
If you look at the dark part of the shadow
You can tell that there is a red feel to it
This part is not directly exposed to light
and only the surrounding lights come in
which makes it have light come out reflected from inside
Because it has a red color inside and reflects that
It gives off a red hue
This complex skin texture
by using more layers here
can be edited more elaborately
There is no exact answer to these numbers
Depending on the individual or according to the studio's internal manual
It may vary
Back to the next light shift
Some of the light passes through objects
It may come out the other way
This case is also called Backscattering
Depending on the renderer, this may be specified separately
In Subsurface Multi Scattering
There is also a way to create it by adding layers
It means the same thing in the end
Let's go back into Maya and do a quick test
Here is a simple object
First, I light the object
with a strong light from behind
Here is the result of the render
To make the color distinction clear
I intentionally added
red to the Subsurface Scattering layer to this object
But if you look here,
Only the right part is slightly red
Overall, the original color, turquoise, is maintained
As you can see here, the thickness of the objects is different
Do you know why?
The thinner the thickness, the easier it is for light to pass through
The color is more visible during transmission
The thick part has significantly less red parts
The thin part allows light to come in from behind
Because it is thin, it comes out with a red color
The red hue feels stronger
This was a rough explanation of the movement of light
Back to Maya
Let me explain another important part
Here's a bump map on Overall
This slot can have two textures applied to it:
Bump map and normal map
Both bump map and normal map
make no deformation to the actual modeling
It only depicts light and dark with a rendered image
I think it could be seen as a kind of optical illusion
Let me briefly explain the difference between the two:
Bump map is a map depicting the elevation of a surface
using the value of the map
that is, white, black, and the middle value
Because it requires values ​​from white to black
Texture maps are created in grayscale
Grayscale has only one channel
Because it only uses one channel
It is described only to the extent that the surface rises and falls
The quality is lower than normal maps
A normal map is literally the normal of a surface
In other words, the direction
There are three channels: red, green and blue
Each represents the X-axis, Y-axis, and Z-axis
Since there are three channels, depending on the direction of the light
The changes in light and shade look more realistic
In Redshift, there is a bump and normal
self-node is created
Drag the normal map in and drop it here
A texture node is automatically created
If you middle click on this part to insert a texture,
A normal node is created
Here again, select Tangent Space Normal
Set the value to 1
And set the Color Space value of the normal map to Raw
Before we start the practice
Lastly, there is one more thing I would like to say
Textures of sRGB and linear type
If we get into this part too deeply,
the explanation gets too long, so I'll make it short
When using textures
it only applies to textures in JPG or PNG format
The color part is related to the texture attribute
Set it to sRGB
The remaining numbers need to be in linear,
Here we have the Raw mode. Let's select Raw.
What I mean by the numbers mentioned here is
In simple terms, these are roughness, metallicity, normal maps, and bump maps
To enter a roughness value in the Roughness item
the roughness map is applied
To express a numerical value for the degree of metal
the metallic map is applied
During depiction on the surface, protrusion or
directionality's numerical value expression
bump or normal map is applied
These maps are expressed in color to the eye, but
Actually, what Maya requires is not this color
It is the color value of each channel
The values ​​from 0 to 255, or in other words, from black to white
These are the ones that were applied by texturing them for input
For items of this nature, select Raw and connect them
The part related to color, i.e.
Diffuse color, Reflection color
And I didn't explain it here, but Refraction color
And this also includes the tint color
The texture connected to this part is
be set to sRGB
Surprisingly, this part is often not followed
These tasks are important in other 3D programs or
Unreal, etc.
You must know this
Especially if sRGB is applied to this normal map in Maya
The change in shape will appear severely distorted
Then simply, in our bear shape
Let's try shading
Before going into the material
There are a few things to prepare
I'll put the design on the side for color specification
You must lay a Plane on the floor
Because indirect light comes through the floor
to the character
If there is no floor
The bottom side just comes out black
For light settings
I Created an object that can be used as a reference
Black, medium gray, white
and chrome material are installed
Objects will be the standard for
controlling the intensity of light
Now let's get into the real stuff
Basically, all will be applied with plastic material
The hat uses Xgen, which we will learn about next time
I'm planning on making a fur hat
First of all, the base was made of plastic
The bell is made of metal
Both plastic and metal can be achieved with just color and roughness
They are materials that can be easily made
In the case of ribbons, it is fabric
The fabric must have an elaborate pattern
Because only then it can create a fabric feel
We will use color map, roughness map and normal map
All downloaded from free texture sites
When applying all three textures
Please strictly adhere to sRGB and Raw formats
With just these three maps
It seems like it would be difficult to implement fabric material
So I added something called Sheen to Reflection
If you give this item a Weight value,
The Fresnel feel comes to life strongly
If you look closely at your clothes, you will see that in the edges
Fresnel is visible
This is the function that gives that effect
The eyes, nose and mouth are made of glossy plastic
This concludes the shading work
Let's summarize what we learned in this lecture
First, we learned about the UV cleanup process
Second, we learned making various shaders
using textures
The process of shading is changing a gray, ugly polygon mass to
a lively character
I've seen a lot of people who aren't confident in shading
As I said before
using Mega Scans, Substance Painter
several texture sales sites,
allows for easier and more advanced shading work
Shading settings and configuration may vary from studio to studio
However, if you have a basic understanding of the content taught in this lecture
I think it will be very helpful when you come across new content
Thank you
Efficiently deploy and organize UVs
Shading: The process of realistically coloring and textureing a gray polygonal mass
Incision is made mainly in areas that are not visible during UV cutting
Checker file: a numbered or square file used to check for sagging or interlocking parts of the face
All modeling seam locations are cut mainly on the back, bottom, and hidden edges
Minimizing UV incisions: The more incisions there are, the higher the chance that distortion will be noticeable
Severely affects the texture resolution and appearance of that part
Minimize empty space in UV window
This is why each texture increases the time when it is rendered
To optimize the asset, it should be created with minimal UV shell space and empty space
Aligning the orientation of the 3D display and UV editor
They must be placed facing the same direction in the UV shell
Also in the UV editor, make sure the shells face the same direction
Additional work is needed when UV shells of the same type are oriented in different directions
Working with UVs using modeling
When working with UVs, you may discover errors that you didn't see when modeling
Expressing textures through shaders
Physically Based Rendering (PBR)
After the introduction of the PBR-based rendering system, there was one established standard shader
Renders by simulating how real light reflection physically occurs
Fresnel Type: When an object reflects light, the reflectivity varies depending on the angle between the observer and the object's surface
At 0 degrees, the reflectivity is low, and as the angle increases, the reflectivity increases rapidly
Metalness If the intensity is 0, it means non-metal, and if it is 1, it means metal
Bump maps and normal maps
Bump map: A map that describes the surface elevations using values ​​between white and black
Normal map: Defines surface directionality, using three channels to adjust light and dark based on light direction