About this project

The Texture Resource Guide is a book that I put together that aims at consolidating a lot of information about making materials for 3D models.  As I taught myself these skills and concepts I found it difficult to find a unified source of information to learn from.  This book could be useful for anyone doing 3D work at the beginner level or even experts needing a reference book.

 If you'd like to get your hands on the book you can buy it HERE

You can also print your own HERE

  • Directions: Print double side (flip on short edge), fold in half, staple in center, and trim excess

For anyone looking to view the content digitally I have posted the book below for your convenience, enjoy!


Rendering by Diego Perez

Rendering by Diego Perez

Hey! Thank you for checking out this book (webpage)

The Texture Resource Guide is meant to be used as a reference for designers, or just about anyone new to the world of 3D modeling and rendering. The main goal of this book is to consolidate a lot of the information there is about material creation, and in turn, provide you with a fundamental understanding of how materials work.  You may have some questions before you get into this book, so I’ll answer those questions now. 

Why should I care so much about materials?  Good materials have the ability to push a great model over the top, and really help tell a story.

Keyshot comes with a great material library, what’s wrong with that?  Nothing! But softwares change, and you might not always have a material library at your disposal, by understanding the fundamentals of what makes a material, you will be able to make great materials no matter what. 

So with that out of the way let’s get started!  First we’ll look at the basics of a material, then the softwares  and tools available, and finally I’ll give some resources so you can learn more. Enjoy!


BASICS

The very basics of texturing and making materials will be the same no matter what software you’re using. The types of maps you use and how you use them will be consistent.  This is why it is important to have a thorough understanding of the fundamentals.


Rendering by The Rusted Pixel

Rendering by The Rusted Pixel

Materials, Maps, Textures, Oh My!

Is a material the same as a texture? It is and it isn’t.  There’s not a straight definition across the board, but for all intents and purposes the terms in this book will be as follows:

A material is the final look applied to the object consisting of all maps (This is referred to as a shader as well).  A texture will refer to an image that is used in the creation of the material (ex: a picture of woven fabric).  A map will refer to an image that is used to create the material as well, but more specifically referring to non-photographic images (ex: grayscale and normal maps).

If this seems complicated now, it’s alright, as we learn the basics, these will become clearer and more familiar.

It is also important to note that the quality of your model is much more important than the quality of your materials.  Good materials can make a great model better, but they can’t be used to cover up a poorly modeled asset. Take the time to learn good surfacing, topology, or construction habits, and then look into material creation.

Let’s get into it!

 


Understanding Grayscale Maps


via textures.com

via textures.com

DIFFUSE

The diffuse map is the most basic and most important map when it comes to good materials. It consists of an image that gives your material the look you’re going after whether it be wood, metal, or paint.

Diffuse maps are probably going to be the easiest part of making a material, the maps are everywhere, because all you need is an image of what you’re trying to make.  Making leather? Just search “leather
textures” in Google and find one that works.
This is also the easiest map type to make yourself.  If you need to match a very specific material, just take a good picture of the material.  Take the image into Photoshop and fix the distortion, color, and crop it to a square.  There you go, your own diffuse map!

It is also important to take into consideration how your map will repeat or tile on your model, for the best results, search specifically for “tileable” images.  This will help hide the map’s repetition.


via textures.com

via textures.com

Reflectance

Reflectance refers to how your material reflects its surroundings. It uses grayscale data from either a solid color or a grayscale image.  You can choose from black to white; white being 100% strength giving your surface a polished chrome look, and black being 0% strength and showing no reflection at all.

Some softwares will allow you to use a map to define the reflectance.  This is a great way to add realism to certain materials, for instance the grout in between tiles is more less reflective than the tile itself (create a map with black for grout, and white for tiles). Maps can also be created to show rough spots in the material’s finish.

A channel inside reflectance is Fresnel, which will be discussed more later in this book.

Glossiness is a channel inside reflectance and will control more closely how the material reflects light sources, giving it a glossy or matte finish.


via Jambox.com

via Jambox.com

opacity 

Opacity also has a few different names from program to program. You may see it as transparency, or even alpha (alpha has other uses as well like cutting out labels).

Opacity maps are grayscale textures that use values from black to white to determine the transparency of the material and the object it is applied to.  These are a great way to save time when modeling and offer a lot of flexibility when it comes to renders.  

A good example is when designing a speaker, the grill of the speaker can have thousands of holes, that would slow solidworks down quite a bit.  By simply modeling the grill as a plane, you have the ability to create an opacity map in illustrator  with the exact grill pattern you want.  If you want to try new grill patterns, just make a new map and render it out.  This does sacrifice some accuracy but can be useful depending on the project.

Opacity maps are also used to create plants, where each leaf is a single plane with an opacity map to cut out a specific leaf shape.


rendering by Tomasz Radczuk

rendering by Tomasz Radczuk

Refraction

Refraction goes hand in hand with opacity.  Glass is almost perfectly clear but how does it show up in a render?  Reflection is one way, and refraction is another.

Let’s use glass as an example, but this is true for any translucent or transparent material.  Glass bends light that passes through it, giving distorted reflections and around the edges and bottom of a glass bottle.

Refraction is controlled by the IoR or the Index of Refraction.  This is a numerical value that defines how light passes through the material.  Air has a value of 1.0001 meaning that light travels near perfectly straight, glass has a value of around 1.5, and water about 1.3.  The value is easy to find for anything by simply searching “IoR of _____.”

If your glass has color (ex: brown beer bottle), that can be added in the fog channel.  The fog amount will define how clear the glass is.  For glass to look more accurate, you will also need to enable Fresnel, which will come later in this book.


Bump, normal, or Displacement?

This is a good question.  All three of these maps do very similar things but  in a different way.  They add detail to your model that you do not have to create yourself.

Bump and Normal maps simulate bumps and details on the surface of your model.  It does not actually change the surface of the model at all, but tells the lighting where to cast shadows and highlights to give the illusions of detail. 

So what’s the difference between bump and normal?
Bump maps use a grayscale image to define the height of the surface. A normal map uses RGB values, rather than grayscale, to position the normals in XYZ space.  While they may look very similar, normal maps offer better accuracy and detail.

Most softwares will let you use them both, so use a normal map whenever possible for better results.  

Displacement works by actually altering the surface of the object on a sub-polygon level. Displacement maps are grayscale images like the bump map.  Displacement should be used when the object is the main focus of your render, and especially if the edges will be prominent.  Displacement maps really show a difference along the edge of the surface they are applied to, while bump and normal maps will leave the edge of a surface perfectly smooth.


via Digitaltutors.com

via Digitaltutors.com

caustics

Have you ever focused a magnifying glass on an ant to make it burn in the sun? No? Just me?

If you have, than you already know what caustics are.  Caustics are how light is refracted by a curved surface, and more importantly, how it is projected onto another surface.  

Adding caustics to a transparent object helps by adding intense concentrations of light within the shadow. Caustics are simply turned on or off in the render settings of the software. 

Volumetric Caustics are a way of projecting focused light beams as they pass through the air, they can be used for a cool stylized effect  like a dusty room, or light beams being cast onto your model.  They also are necessary for underwater scenes, where they provide the most accuracy.

Be warned, however, that adding caustics to your scene will greatly increase your render times.


via Digitaltutors.com

via Digitaltutors.com

Subsurface Scattering

Subsurface Scattering (SSS) is a little bit like caustics.  It works with translucent materials, and it calculates how light is scattered within the object, and how it exits.  

Most materials only allow light to interact with the surface of the object.  However, some materials allow light to be absorbed and re-emitted at a different point.  This is recreated with SSS. A good example is skin; only 6% of direct light is reflected at the surface, while 94% is through SSS.
This tool is very useful for recreating skin as well as wax,  stone, and some liquids.

SSS is relatively new and so is not supported by all softwares. However, it is still a good property to understand if you need to utilize it.

(Maxwell Render groups this property with BSDF, and has some more settings involved) 


via Fxguide.com

via Fxguide.com

Fresnel

The Fresnel effect is the observation that the amount of reflectance a surface has depends on the angle it is being viewed from.  

Think of it in terms of water, when you look at a puddle in the distance, you can see it reflecting its surroundings as well as the sky, yet as you walk closer to the puddle, the ground beneath it will become more visible.  This is because of the Fresnel effect.


The Fresnel settings can usually be found in the reflectance or specular sections of a material editor.  While it is a great way to add realism to liquids, just about everything has Fresnel. Don’t be afraid to use it on any material, everything from paper to car paint could use it(In Vray it is on by default for every material).  This will be especially evident if you are doing any sort of animation or movement of your object.


rendering by Alek Gurkan

rendering by Alek Gurkan

Cel & Toon

Cel Shaders and Toon Materials are a great way to get an illustrated look for your model.  They do so by eliminating glossy specular in favor of hard edged highlights, and hard transitions from light to shadow.

Cel shaders have a lot of settings in order to achieve a wide variety of results.  Everything is possible from an outline around the edges of your model (like the toon material in Keyshot)to a fully shaded scene like shown above. Cel shaders vary by software, but one of the best softwares for them is Cinema 4d.  It is used by a many illustrators to give a great stylized look to their models.  

These style renderings could come in handy for product designers to do a more explanatory rendering of their product.  For instance, an exploded view with color coded parts.


via Keyshot.com

via Keyshot.com

Luminance

The luminance channel on a material dictates the material’s light intensity. It  is also referred to as emissive in some softwares.

When enabled, the object that your material is applied to will emit light. You can set the intensity of the light as well as the color.  Luminous materials can serve as light sources like a bulb in a flash light or a neon tube. Luminance can be tricky sometimes, and may take some playing with to get right.
If you want your material to light up another object in your scene, make sure global illumination is enabled, as well as giving the material a high light intensity.  

However, there are some effects that the renderer can not recreate.  Effects like light bloom, lens flare, and bokeh are all able to be easily added to a render in post-production.  Although Keyshot does have a bloom radius setting in the render settings.


rendering by Lee Griggs

rendering by Lee Griggs

Ambient Occlusion

Ambient Occlusion (AO) is essentially shadow data that does not depend on a light source.  It is calculated based off of how much ambient light a surface receives.  Ambient light is light that is not explicitly created by a directional light source, but rather comes from all directions. 

AO could be considered more of a rendering component rather than a material, but it will impact the look of your material.  Some rendering softwares have AO channels in their material editor, or AO toggles in their render settings.  They work differently, but will have the same end result.

AO is used to add realism to models by simulating the ambient light that would be lost otherwise.  Looking at the above image as an example, you can see there is no directional light in the scene.  The scene is only shaded by AO, the areas that appear darker, appear so because they receive less ambient light.  You can also think of it as an overcast day, the sun isn’t shining anywhere particular, but the entire sky is emitting some uniform light


via Digitaltutors.com

via Digitaltutors.com

Mapping

Textures exist on a separate coordinate system than 3d geometry does, with U, V, and W representing the X, Y, and Z axes. The reason being that a texture’s position is relative to the geometry’s position.

Once you’ve got the material you want, it’s time to apply it to your model, but how does the software know what to do?

You can tell it by mapping.  Mapping gives the software a rough idea of how textures should be applied on the model.  Some models can be mapped with primitive shapes like cubes, cylinders, spheres, and planes.  This is how Keyshot lets you apply textures.  The down side is that this is limiting for more organic shapes.

Some more complex models have to be unwrapped and laid out on a 2D (UV) plane in order to be textured properly.  This is only possible on polygonal models. Textures for game assets are made with this technique and are organized to fit multiple materials on one texture file.

more info on UV mapping here


via DigitalTutors.com

via DigitalTutors.com

Baking

Baking is a technique used mainly for game development and VFX.  It’s used to simplify the geometry and/or lighting in scenes that need to be processed by your computer.

In normal baking you take a more detailed model (high poly)  and project its details onto a less detailed model (low poly).  This is done through normal maps.  Normal baking is shown in the rendering above, notice the complexity in geometry vs. the surface details.

Light and shadow can also be baked through diffuse maps and work somewhat the same way by taking a lit surface and transferring the projected light and shadow onto an unlit surface.

The reason this is important for games is because every polygon in a model takes time for the computer to render, so the fewer the better, and faster the game will be.  

Baking may not be of much use to industrial designers, but it does help understand how you can use these texture maps differently.


via Marmoset.co

via Marmoset.co

PBR & PBS

If you got excited when you saw PBR & PBS in the table of contents, then you’re really going to enjoy the beauty of physically based rendering and physically based shaders.  

Why does this matter?  Recently PBR has been somewhat of a buzzword because it gained support in game engines like Unity and Unreal.  If you’re not interested in game design, then pretty much all of your options are already physically based (Keyshot, Vray, Maxwell).


If you are interested in game design, then it helps to be familiar with the different map types and terminology used in physically based shaders.  It is a little more complex than the scope of this book, but Marmoset Toolbag does a great job explaining it for anyone looking to learn more about it.


Additional Basics

Anisotropy

Anisotropy is a material parameter that gives directionality to the material’s reflections.  This is not a physically accurate effect, but is an easy way to recreate some brushed or smudged surfaces.  It can also be mapped to control the rotation.

Resolution

Textures maps should be created in square (1:1) aspect ratios.  This makes tiling the texture more consistent.  Common texture resolutions are powers of two,  for example: 256 x 256 ... 512, 1024, 2048, 4096 and so on.  Using these resolutions will ensure that your texture will be easily translated into a material in any software and prevent difficulties down the road.

Procedural

You may see some materials with the label “procedural” what this means is that rather than relying on a specific image, the textures are created procedurally by the program.  What this means is that a procedural wood texture can be applied to a large surface without being pixelated or showing where the texture repeats.  Just about any material can be procedural, cloths and woods are among the most popular ones.



Software

Now that you’ve learned the basics of texturing, you’re better suited to use just about any rendering software! In this section I’ll go over some of your options for texturing and rendering.


via Keyshot.com

via Keyshot.com

KEYSHOT

Keyshot is probably one of the best known rendering softwares among industrial designers, it caters well to new users and offers great flexibility for more experienced users as well.

THE GOOD: Keyshot offers really great results right out of the box.  Its easy to use interface makes it less intimidating for new users.  The built in material library goes a long way in servicing most of a designer’s needs. It also has all basic material channels for creating custom materials, and with the new updates in Keyshot 6, like the material graph, users have a lot more power to create quality materials.  Some other features to look for in Keyshot 6 include better labels , and material animations (like animating a light turning on and off or changing colors)

THE BAD: While Keyshot is capable of producing beautiful renders, there is only so much it can do.  It does limit the user in a few aspects such as displacement maps, and overall material detail.  The mapping tools go a long way, but can still leave some texturing errors on more complex models.  Lastly, because it operates as a standalone program, the scene will not update along with your model, but this is easily fixed with the plug-ins they’ve developed.

BEST USES:  Keyshot is great for quick results when you don’t have time to experiment with texture settings and different map types.  It also helps you get very consistent results which is important if you’re presenting multiple  iterations.  So if time is of concern, and materials aren’t the biggest issue, then Keyshot is a great tool for your needs.


via Lemanoosh.com

via Lemanoosh.com

VRAY

Vray is an industry standard for many professions, meaning its community is huge and there’s an answer for just about everything. It operates as a plug-in for a wide variety of CAD programs.  What sets Vray apart from so many other softwares is its great lighting.

THE GOOD: Users who choose Vray are usually looking for high levels of photo-realism.  Vray is preferred because of its in-depth material creation, which allows highly specific materials that users can’t create elsewhere.  It is also known for its indirect lighting (while it’s very important, it doesn’t have much to do with material creation).  Since the community is so big, there are thousands of materials available for download, and plenty of help to get just the right settings.  Also, since it is a plug-in, you won’t have to worry about continuously importing new models if your preferred program is supported.

THE BAD:  Vray can be daunting at first glance, there are a lot of settings that require commitment to get right and to remember. Because Vray is a plug-in, not all versions are created equal.  For instance, the 3DS interface is already suited for rendering, making the plug-in an easy adaptation, while Rhinoceros is not meant for rendering, so Vray’s interface can be tougher to navigate, all the same settings exist just in different locations, and results will still match among the different programs.

BEST USES:  Vray is a great tool for someone looking to take their renders outside of what Keyshot can do.  It’s worth the time it takes to learn because it is becoming more widely used by product designers. After spending the initial time it takes to learn, scene setup and product renders can become as easy as Keyshot.


via Allegorithmic.com

via Allegorithmic.com

Substance Designer & Substance Painter

Unlike the previous softwares listed, these are not for rendering, these two are only for material creation, and are very powerful.  Subtle imperfections and details in textures can really help with photorealism, and with the tools in these two softwares, the possibilities are endless.  These softwares are gaining popularity among game developers because of how they simplify physically based shaders.

THE GOOD: Substance designer offers a node based approach to material creation, making the materials completely parametric. Want your paint to have a different brush pattern? Just a few small adjustments can do it.  It comes loaded with tons of maps and generators that can be used to create very specific materials that you then export for use in any renderer.

Substance Painter allows you to load a model (.obj) and paint directly onto it.  What’s great is that a brush can effect your diffuse, specular, and normal all at once, making detailed textures much more quickly than Photoshop alone.  Once you’re done making the texture, just hit export and you’ll get all of your maps output for use in any software

THE BAD:  Both programs have so much functionality that if you don’t have a clear vision of what to do, you may not know when to stop.  Painter requires that you unwrap your model before painting, but for designer that is not necessary.  Both softwares are relatively new, so finding tutorials can be difficult as well.

BEST USES:  If you need to give your model a little bit more character, like scratches, dents, or rust spots, then the Substance suite is a great way to get results. Allegorithmic also offers substance share, where you can download really great materials, maps, and brushes  made by the user community.


rendering by Wiktor Ohrman

rendering by Wiktor Ohrman

Quixel Suite

If you really liked the sound of the Substance Suite, but learning a completely new software doesn’t sound appealing right now, you’re in luck.  Quixel Suite works very similar to Substance Painter, but it operates as a Photoshop plug-in.  It offers the same ability to paint directly on a mesh model.  Quixel boasts the realism of its scan-based materials.  The program includes an immense library of textures to use, as well as smart materials and brushes.  Quixel is younger than Substance, so big things can be expected as it continues to grow.

THE GOOD: Quixel has a much easier learning curve compared to Substance, because it operates inside of Photoshop.  The pre-loaded material library covers about 1000 materials that are all physically accurate. If that isn’t enough, you can still create your own materials to use in the program.  It also comes with NDO, a normal map creator that incorporates a number of tools to be one of the best options for normal creation.  Having knowledge of Photoshop’s brushes, selections, and layer settings will be a huge plus when starting out.

THE BAD:  This workflow still requires that you unwrap your model prior to painting.  While it does have a large library, it does not contain everything and is slowly growing.  The simplicity makes it a bit more limited than the Substance Suite. Early versions of Quixel were notorious for being very buggy, which is a problem the developers are still working to fix.

BEST USES:  Similar to the best uses of Substance, but with the special interest of a faster workflow.

Other good software

Cinema 4D

Modeling, animation, and rendering software.  Top pick for graphic designers and illustrators seeking more stylized renders.  Has great cel shader capabilities as well.  In addition, Cinema 4D comes with Bodypaint, a plugin that allows you to paint directly onto your models.

Crazy Bump

Software that quickly takes bitmap images and converts them into full materials with accurate normal maps, specular, and ambient occlusion maps.  The software has a few tools to help get the maps just right, but is overall very easy to use.

Marmoset Toolbag

Mainly for material editing.  It is a realtime render engine (somewhat like Keyshot), with a variety of material creation tools.  You can import a model and begin to create the materials for it that you paint directly onto the model.

Ptex

Developed by Disney Animation Studios.  It completely transforms the texturing workflow, and makes it faster than ever.  Ptex stands for: per-face texture assignment, and what it does is eliminate the need for UV unwrapping your models.  It is capable of creating much higher resolution textures without seams.  Autodesk Mudbox support Ptex painting, and render softwares including Vray are gaining support for it as well.

Unity

Known as a game development software, but has expanded for many more uses including product visualization. By allowing users to create highly interactive programs, it takes product presentations to another level.

Unreal Engine 4

Unreal Engine is a lot like Unity.  Users say it is a bit easier to pick up as a beginner with little or no game experience.  The beauty of UE4 is that it is 100% free including technical support.  The charge comes for developers who release games, but using it for visualization is completely free. Keep in mind that both Unreal and Unity work with physically based shaders, so your workflow will change, but by using either Substance or Quixel, the transition will be easy.

Zbrush

Zbrush made this list because of its UV unwrapping tools.  It ships with a plug-in called UV Master that makes unwrapping a breeze, and great for organic models.  While the user doesn’t get great control over the unwrapping, it gives quick results that are great in a pinch. Zbrush also allows you to paint directly onto your model.  This makes for a much simpler workflow which allows you to go from sculpting to unwrapping to texturing without leaving.


Resources

The end of the book had a few relevant resources for further learning, so I will direct you to My Resource Collection to find any further help.


Thanks for reading!

I hope you enjoyed this, if you have any comments or critiques I would love to hear them so I can continue to improve! Reach out to me (contact info here) and let me know!