UV Maps Explained
Summary
TLDRThe video script delves into the intricacies of UV mapping in 3D game development, a process that bridges the gap between 2D textures and 3D models. It explains the necessity of UV mapping due to the non-existence of true 3D images and the limitations of 2D images in 3D spaces. The script introduces the concept of 'unwrapping' models, akin to flattening a folded piece of paper, and discusses the strategic placement of seams to optimize texture space. It differentiates between game and film UV mapping, emphasizing the performance optimization required for real-time rendering in games. The series promises a deeper exploration of UV mapping techniques with a focus on game development.
Takeaways
- 🎮 Video games involve complex topics, including the concept of UV mapping for 3D models.
- 🌐 UV mapping is a technique to project 2D images onto 3D models, despite 3D images not existing in a usable form for games.
- 🖼️ In 2D games, images (sprites) are used directly as they are in the same dimensional space, requiring minimal preparation.
- 📐 The necessity of UV mapping arises because 3D models exist in 3D space, but textures are 2D, creating a dimensionality mismatch.
- 🛠️ UV mapping acts as a 'translator' between 2D textures and 3D models, allowing them to work together.
- 🔄 The process involves bringing the 3D model into a 2D environment (texture space) to apply textures.
- 🔲 UV mapping coordinates are referred to as U and V to avoid confusion with the 3D space's X, Y, and Z coordinates.
- 🎨 Unwrapping a model is akin to flattening a 3D object into 2D for texturing, similar to the art of origami but in reverse.
- 👕 Seams in 3D modeling allow for non-destructive 'cuts' to help in unwrapping models effectively, much like seams in a shirt.
- 💻 UV unwrapping in games focuses on optimization for real-time rendering, unlike in film where artist speed is prioritized.
- 🔄 The series will delve deeper into the practical aspects of UV mapping, starting with hands-on experience in a modeling application.
Q & A
What is UV mapping in the context of video games?
-UV mapping is a technique used in 3D modeling to project 2D images (textures) onto 3D models. It serves as a translator between the 2D textures and the 3D models, allowing artists to apply textures to the surfaces of 3D objects.
Why is UV mapping considered a bottleneck for both beginners and experts in 3D modeling?
-UV mapping is complex due to its requirement to map 2D textures onto 3D surfaces, which involves understanding both 2D and 3D spaces. It requires careful planning to optimize texture use and can be challenging to execute efficiently, making it a bottleneck.
How does the concept of UV mapping differ from the use of images in 2D games?
-In 2D games, images (sprites) are already in the same two-dimensional space as the game, so they can be directly used. In contrast, UV mapping is necessary for 3D games because it bridges the gap between the 2D texture space and the 3D model space.
What is the purpose of unwrapping in the context of 3D modeling?
-Unwrapping is the process of flattening a 3D model's surface into a 2D plane to apply 2D textures. It allows artists to map texture coordinates onto the 3D model's surface, which is essential for texturing.
Why do we need to bring 3D models into a 2D environment for texturing?
-Bringing 3D models into a 2D environment for texturing simplifies the process because it allows artists to work with textures in a more familiar and manageable 2D space, despite the model's 3D nature.
What are the challenges faced when mapping 2D textures onto 3D models?
-Challenges include accurately representing the 3D surface on the 2D plane, avoiding texture distortion, and optimizing texture use within the constraints of real-time rendering in games.
How do seams in 3D modeling relate to the process of unwrapping?
-Seams are virtual lines that indicate where the 3D model's surface can be cut to flatten it into a 2D plane for texturing. They guide the unwrapping process, similar to seam lines on a piece of fabric.
What is the significance of the terms 'U' and 'V' in UV mapping?
-In UV mapping, 'U' and 'V' represent the horizontal and vertical dimensions of the texture space, respectively. They are used instead of 'X' and 'Y' to avoid confusion with the 3D model's coordinates.
How does the approach to UV unwrapping differ between film and game industries?
-In the film industry, unwrapping focuses on ease of texturing with less concern for texture space optimization. In gaming, due to real-time rendering requirements, UV maps must be optimized for performance, leading to more compact and efficient unwrapping.
Why is optimization important in UV mapping for games?
-Optimization in game UV mapping is crucial because it ensures that textures use memory and processing power efficiently, which is necessary for maintaining high frame rates and performance in real-time gameplay.
What can we expect to learn in the rest of the series about UV mapping?
-The rest of the series will delve deeper into how UV mapping works, including practical demonstrations of unwrapping 3D objects and strategies for optimizing UV maps for game development.
Outlines
🎮 Understanding UV Mapping in 3D Game Design
This paragraph introduces the concept of UV mapping in 3D game design, explaining its necessity due to the non-existence of true 3D images and the limitations of using 2D images to represent 3D models. UV mapping acts as a 'translator' between 2D textures and 3D models, allowing artists to project 2D images onto 3D surfaces. The process involves unwrapping 3D models into a 2D plane, which is likened to the process of folding and unfolding paper in origami, but in reverse. The paragraph also touches on the difference between UV mapping for games and films, emphasizing the need for optimization in games due to real-time rendering constraints.
🔍 Deep Dive into UV Unwrapping Techniques
The second paragraph delves deeper into the mechanics of UV mapping, focusing on the unwrapping process. It uses the analogy of origami to explain how 3D models are 'flattened' into a 2D space for texturing. The concept of 'seams' is introduced, which are virtual cuts that help in the unwrapping process, similar to how seams in a shirt allow it to be constructed from separate pieces of fabric. The paragraph highlights the importance of efficient UV unwrapping in game design due to the limited texture space available, contrasting this with the more spacious unwrapping in film where real-time rendering is not a concern. The summary also sets the stage for a practical demonstration in a future video, where a 3D object will be unwrapped in a real-time modeling application.
Mindmap
Keywords
💡UV Mapping
💡2D Images
💡3D Models
💡Texture Space
💡Unwrapping
💡Seams
💡Polygonal Faces
💡Sprites
💡UV Editor
💡Optimization
💡Real-time Rendering
Highlights
UV mapping is a complex technique for projecting 2D images onto 3D models.
UVs are not related to solar UVs but are essential for game development.
2D images are used to represent visual data in games, called sprites or textures.
3D images do not exist in a way usable for games, leading to the necessity of UV mapping.
UV mapping acts as a translator between 2D textures and 3D models.
3D models are made of polygonal faces existing in geometric or 3D space.
Textures are brought into the texture space, separate from 3D space, to apply them to models.
UV mapping coordinates between 2D pixels and 3D space.
Major modeling applications have UV editors to simplify the UV mapping process.
UV mapping involves unwrapping 3D models into a 2D space for texturing.
Unwrapping a model is likened to the art of origami, but in reverse.
Seams are used in 3D modeling to indicate where to make cuts for unwrapping.
UV unwrapping for games is performance-oriented due to real-time rendering constraints.
UV maps in games need optimization to fit within the limited texture space available.
The next video will provide a hands-on look at unwrapping a 3D object.
Transcripts
video games
are complex understatement of the
century right
perhaps one of the most complex topics
that is a universal bottleneck
for beginners and experts alike is the
concept
of uvs now i'm not talking about solar
uvs
although game developers could stand to
get a few more of those
i'm of course referring to uv mapping
a technique used within the digital
space to project
2d images onto 3d models
that may not mean much to you as of
right now so before i get into
explaining what uv maps are
let's first look at why they exist to
help us form an understanding
you are likely aware that to hold and
represent
visual data within games we use images
depending on the type of game we are
making we often call these images
something different
such as sprites for 2d games and
textures
for 3d games at the end of the day they
are all simply image containers
which hold pixel color data that we use
to display
artwork let's start with how we use
and display these images within a
completely 2d game
in a two-dimensional space the only
dimensions we are concerned with
are the width and the height our x and y
dimensions or directions respectively
well we know that digital images are
two-dimensional right
so since our image is already in the
same dimensional space
there is very little we need to do in
order to actually prepare it
simply importing the images and setting
them up as sprites
within your chosen application is most
often as much as it takes
so if we extrapolate that knowledge a
little bit
for 3d games it would make sense to
utilize images
in the same dimensional space right
except what exactly is a 3d image
here lies the real reason why uv mapping
is used
and for many working in 3d is a
necessary evil
3d images do not exist at least not yet
nor in the capacity that could be usable
for games
and due to the nature of using 2d images
to store our textured data
we are inadvertently limited by the
dimensions of said resources
to circumvent this limitation the
process of uv mapping was developed to
be what i will call
a translator between our 2d textures
and our 3d models in most instances
creating a 3d model requires the
development of polygonal faces
to represent the surface of the asset we
are making
in a modeling application these polygons
would exist
in what is referred to as the geometric
space
which i'll just call 3d space in order
to use textures on 3d models
we need to bring one dimension into the
other
because it is much easier to lose a
dimension than add one
we opt for bringing our 3d model into a
2d environment
this environment is called the texture
space separate from the 3d space
and it is where we will be able to
visualize both our 2d
and 3d assets together
this environment allows us to bring in
our textures
and position the polygons of our models
to capture the image data
essentially we're mapping coordinates
between 2d pixels
and 3d space all done via our texture
space translator
now i know you're probably thinking wow
that's pretty complex
and you're right it is complex however
in your day-to-day life you simply won't
be interacting with uv mapping in this
way
all major modeling applications already
have their own implementations on how to
tackle this obstacle in more elegant
ways
by interfacing it as a uv editor
fundamentally it is
all using this underlying theory of
translating between texture space
and 3d space like i've mentioned in a
two-dimensional plane we refer to these
dimensions as
x and y however when we operate in 3d
we also use x and y with the addition of
our third dimension
z now normally this is fine
as the 2d x and y dimensions can be
easily translated to 3d coordinates
but the x and y dimensions of the
texture space
are not directly corresponding to
coordinates
in 3d space but rather represent
coordinates on the polygonal faces
of our models so in order to avoid
further confusion by using
x and y naming conventions in our
texture space
it was decided that we would instead
refer to the horizontal
and vertical dimensions as u and
v respectively that's where the term
uv map actually comes from
now this has been why uv mapping exists
but how does it actually work we'll be
looking at this question in much more
depth over the rest of the series but
essentially the process of uv mapping
is what allows artists to unwrap
their models and provide them textures
again that may not be an immediately
satisfying answer
so let's unpack what unwrapping a model
means
let's first look at origami the art of
paper folding
it may not look like it but origami and
uv mapping are actually
incredibly similar albeit in the reverse
order
for sake of argument origami starts in a
two-dimensional space
as a flat piece of paper the process
that then proceeds to unfold
or rather fold is the transformation
from a 2d item
the one that exists within the 3d space
now obviously the paper exists within
the 3d space the entire time
however the concept remains the same
with 3d models we already have our paper
folded
into our design but we need to find a
way to take our paper and flatten it
back out
to a two-dimensional item modeling
applications provide us the ability
to insert what are called seams you have
probably heard this term before
likely relating to seeing a texture
misaligned on a model where you can see
the seam
line what seams allow us to do is
non-destructively tell our application
where to make cuts along the faces on
our model
to better unwrap it in its attempt to
flatten a 3d model
into a 2d space origami may be difficult
to picture here
so we can also think of inserting seams
as the seam lines of a shirt
in order to flatten out a model we may
need to entirely cut off
various areas of our model from other
parts
much like how the fabric for a shirt is
in separate pieces
before it is stitched together at the
seam lines
now there is no right or wrong way to
add seams
as we will learn in the series however
there are certainly better methods
and rules of thumb that artists follow
to maximize their space
since games often have a very finite
amount of space available for us
on rap as we unwrap more and more parts
of a model
the more crowded our texture space will
become
here is where film and games begin to
differ a little
unwrapping for films is more oriented
towards making texturing far
easier for the artist as there really is
no limit to the amount of textures they
can use
since everything is not rendered in real
time the optimization here is that an
artist that can texture quicker
is an artist that can work faster
because of this
uv unwraps of models can look rather
spacious
and somewhat easy to identify even at a
sheer glance
for games this is simply not the case as
they need to be rendered at 30 to 60
frames per second
in real time with potentially multiple
players
and possibly thousands of other textured
assets
therefore there are incredibly harsher
limitations as
uv maps are intended to be optimized for
performance instead
this will be where the focus of this
series lies and understanding how we can
unwrap uv maps with a game oriented
mindset
in the next video we will have our first
hands-on look
at unwrapping a simple 3d object to see
what it looks like
in a real-time modeling application
Посмотреть больше похожих видео
Blender Beginner UV Unwrapping Tutorial (Chair Part 7)
NERFs (No, not that kind) - Computerphile
[UNITY] Атласы спрайтов
Introduction to OOPs in Python | Python Tutorial - Day #56
Blender Jack O'Lantern Pumpkin Tutorial | Polygon Runway
#1 Struktur Data Tree (Pohon) & Graph (Graf) - Berpikir Komputasional Kelas 9 | Informatika Fase D
5.0 / 5 (0 votes)