Texture painting tips and workflow

• You can paint on 3d objects in Maya and Phototshop
• Use a variety of brush shapes
• Use a variety of opacities 
• Sample from existing textures with the clone and pattern stamp tools
• Blend layers on top of each other
• Paint texture guides in advance in Maya
• Use a wacom tablet
• Use photoshop brush textures
• Use crazy bump to generate normal and spec maps
• Use high quality rendering and lighting in Maya to see normal and spec.

Workflow

1. Layout UV's
2. Paint base colors in 3d (optional)
3. Perform UV snapshot and/or establish photoshop network
4. bring snapshot into Illustrator for vector work
5. add new layers in photoshop, begin painting base texture patterns using guides
6. add new layers in photoshop, sample and clone from source material
7. blend layers together using blend modes and opacity changes
8. save PSD, update network in Maya
9. Correct texture seams using Maya or Photoshop 3d paint
10. use final color map to generate spec and normal maps using crazy bump.

Week 3 lecture

• creating photoshop networks
• painting textures in photoshop
• process:
• establish base color layers
• sample (clone) patterns from image files
• blend
• on 2d image
• on 3d object
• painting textures in maya
• using 3d paint tool to establish texture guides
• removing texture seams
• offset filter
• live 3d cloning
• blending procedurals and bitmaps
• crazy bump
• intro to Mental Ray

Project 2 - Battle Scene

https://www.dropbox.com/s/gqg1esnu3tdm4x7/battleScene.mb

Project 1 details

To submit:

• 1 rendered image at 1280 x 720 resolution - JPG
• Maya scene
• Textures

Details:

• make a floor plane and use color and bump maps to texture it
• Apple should have procedural color and specular maps
• Use layered texture with ramp, fractal and cloud textures for the material's color
• Change blend mode to multiply for each layer except the bottom
• Reduce alpha of each until balanced
• Feel free to connect either the cloud or fractal to the specular color of the material.
• Book should have bitmap color and bump maps
• book should have a logo and leather or fabric material
• Cup should have color map
• cup should have logo, name and some dirt/grime painted on
• Render scene with three-point lighting and raytraced shadows
• Key light = warm directional light, which casts raytraced shadows, high intensity
• Fill light = cool point light, no shadows, lower intensity
• Rim light = spot light
• ray traced shadows can be activated in the Maya Software section of the render settings.
• open your rendered image in photoshop and look at the histogram to view light/dark balance

Directory structure for Project 1 submission

• /Greg Lemon
• /Project 1
• /renders
• project1_render.jpg
• /textures
• cup_color.png
• cup_bump.png
• etc...
• scene.mb

Shader naming conventions:

All shaders should be named "MAT_objectName", where object name is replaced by book, cup, etc

All external texture files should be named "objectName_color", "objectName_bump", etc. 

Final render look

Greg's work

http://greglemon.com/

http://greglemon.tumblr.com/

Chair and Book, Apple and Cup scenes

Below are links to the first two maya files you will need for the class. We'll be using both for in-class exercises, as well as your first project.

Chair

Book, Apple and Cup




Obj versions...chair....cba

UV distortion textures

Here's an example of a UV distortion texture...

You can find more on google images.

UV distortion textures can be used as a texture map so as to check for distortions, seams and other texturing errors. The general idea is that the letters/numbers and grid are familiar shapes, so it's very easy to see when the texture is getting stressed or distorted when applied to the 3D model.

Three objectives of good texturing:

Three objectives of good texturing:

1. Define and support the material.
• flat, shiny, metal, skin, etc
2. Define manufacturing details
• stitches, seams, bolts, grain, screws, logos, borders, etc
3. Define age and decay.
• rust, frayed fabric, burns, spills, stains, etc

CG Talk gallery...

intro to Materials and UVs

Materials

In 3D computer graphics, two things define the surface quality of an object - light and materials. Think of a material as a coat of paint. Just like some paints are glossy and some are matte, Maya's materials allow you to simulate shiny, glossy or flat (matte) surfaces.

The three most common types of materials are lambert, phong and blinn.

Lambert - no specular data, ideal for flat (matte) surfaces.

Phong - glossy material, good for glass and shiny plastic

Blinn - highly specular material, good for metals and certain types of glass

When you first create and object in Maya, the default Lambert1 shader gets applied to it. You should immediately assign a new material to it, otherwise any changes you make to Lambert1 will affect all new objects created in the scene.


UVs
http://en.wikipedia.org/wiki/UV_mapping

http://wiki.polycount.com/TextureCoordinates

http://blog.machinimatrix.org/the-basics-of-texturing-i/


Overview

The best analogy for UV mapping is that you are essentially taking a 3D shape and flattening it out so it can be textured in 2D space. This is much like how a bear-skin rug works; the bear used to be a 3D creature, but once it was pelted, the furrier converted it into a flat 2D shape.

UV mapping, along with rigging, is considered to be one of the more difficult and time consuming tasks in the 3D pipeline. The secret is, it doesn't have to be! If you spend some time planning and thinking ahead, you can minimize alot of errors and rework, and in many cases, achieve good UV layout in a short amount of time. Stay positive and remember that there are PLENTY of UV mapping tools, tips and tutorials online.

Maya's UV projection functions
Maya has 4 main UV projection functions - planar, cylindrical, spherical and automatic mapping. Many times, you will have to use several of these techniques in order to completely map the object. Consider the shape you are trying to capture in 2d space, and think about what kind of projections would best capture that shape.

The three-way battle...
UV mapping is a three-way battle. You are fighting between...

1. Less distortion, meaning that you want the 2D UVs to match the shape of the 3D face they represent as closely as possible.
2. Fewer pieces, meaning that you will ideally end up with fewer UV islands and borders, potentially reducing visible seams.
3. Maximizing texture space, meaning that you are trying to utilize as much of the 0 to 1 UV space as you possible can, so you can squeeze in extra juicy texture goodness!

Mapping early on non-deformed objects

Mapping objects that have not yet been deformed or translated/rotated away from the origin will usually result in cleaner and easier UVs. Consider a curved tree branch; this could most likely be easily mapped using cylindrical projection if it was not curved, but mapping the UVs after the deformation would be more difficult.

Auto mapping

Maya's automatic mapping is okay, but there are much better options for auto-unwrap out there. Maya's bonus tools features an amazing UV unwrap tool, and zBrush has a similar tool called UV master, which allows you to paint where you want the UV seams and edges to be. Feel free to use these tools for you final project if you feel it speeds up your workflow.

Maya's select > convert selection menu

Maya's select menu (in the hotbox, far left) features an awesome convert selection tool, which lets you covert selected components into another component type. For example, if you have a set of faces selected, but you want to select the UV's associated with those faces, go to select > convert selection > to UV's.

GA 3311 syllabus

The Art Institute of California – San Francisco

Course Syllabus

Course Number: GA3311

Course Title: Material and Lighting

Class Meetings: Fridays 8am - 12 noon

Session/Year: Summer 2013  

Instructor Name: Greg Lemon

Email Address: glemon@edmc.edu

Phone: e-mail please

Instructor Availability Outside of Class: TBA

Material & Lighting

Course Description:

In this class, students will be introduced to materials, textures and lighting strategies to add detail and realism to objects without adding complexity to the model. Students will simulate real world surfaces containing reflection radiosity and other effects.

Course Length:   11 Weeks

Contact Hours: 44 Hours

Lecture:   22 Hours per week

Lab: 22 Hours per week

Credit Values: 3 Credits

Quarter Credit Hour Definition

A quarter credit hour is an amount of work represented in intended learning outcomes and verified by evidence of student achievement that is an institutionally established equivalency that reasonably approximates not less than:

(1) One hour of classroom or direct faculty instruction and a minimum of two hours of out-of-class student work each week for 10-12 weeks, or the equivalent amount of work over a different amount of time; or

(2)  At least an equivalent amount of work as required in paragraph (1) of this definition for other academic activities as established by the institution including laboratory work, internships, practica, studio work, and other academic work leading to the award of credit hours.

Course Competencies:

• Upon successful completion of this course, the student should be able to:
• Apply traditional paint concepts, tools, and techniques for use in computer animation.
• Create textures through the use of digital cameras and scanners.
• Use advanced painting techniques such as smudge, burn, clone, and fractals to create complex textures.
• Develop critical ideas for surface treatment, lighting, and motion of 3D models.
• Demonstrate the rules of surfacing 3D images.
• Use multiple image map types on a 3D model.
• Demonstrate the use of local vs. global lighting.
• Execute the lighting of a complex scene with coverage from pre-production to teardown.
• Use textures and mapping to conceal low polygon count.
• Analyze and evaluate and apply texture mapping strategies.
• Understand and apply UVW mapping coordinates.
• Use image manipulation software to create tile able, color-limited maps.
• Use layered image maps for realistic and industrial texturing.
• Understand bitmap and procedural textures and the applications of each.
• Paint organic creature textures.
• Paint character accessories.
• Paint natural textures.
• Paint displacement textures.
• Paint light gels.
• Correlate real light with the computer rendition of light
• Demonstrate the use of reflective lighting.
• Lighting for live action vs. 2D and 3D back plates.

Course Prerequisite(s): MA1134 Principles of 3D Modeling

Text(s): Digital Lighting and Rendering, by Jeremy Birn, Pearson Education (2000) ISBN: 1562059548

3D Lighting: History, Concepts, & Techniques, by Arnold Gallardo, Charles River Media (2000) ISBN: 1584500387

Digital Texturing & Painting, by Owen Demers; Pearson Education (2001) ISBN: 0735709181    

Materials and Supplies: Note taking material, blank CDs or CDR.    

Estimated Homework Hours: 4-6 hours per week.

Technology Needed: PC/NT, Maya, 3D studio Max, PhotoShop.    

Grading Scale:

All assignments must have clear criteria and objectives to meet. All students shall be treated equitably. It will be that student’s right to know his/her grade at any reasonable point that information is requested by that student. The criteria for determining a student’s grade shall be as follows (on a percentage of total points basis):

A 100-93

A- 92-90

B+ 89-87

B 86-83

B- 82-80

C+ 79-77

C 76-73

C- 72-70

D+ 69-67

D 66-65

F 64 or below

Process for Evaluation:

• Attendance and Participation- 10%    
• Assignments and Exercises - 10%    
• Project 1 - 15%
• Project 2 - 25%
• Project 3 - 40%

Student Evaluation/Grading Policies:

• Class time will be spent in a productive manner.
• YOU CANNOT MISS 3 OR MORE CLASSES OR YOU WILL FAIL
• Grading will be done on a point system.
• Points for individual activities will be announced.
• All work must be received by the set deadlines.
• ABSOLUTELY NO WORK WILL BE ACCEPTED AFTER THE FINAL CLASS MEETS WEEK 11.

Classroom Policy:

• No food allowed in class or lab at any time. Drinks in sealable bottles allowed in classroom.
• Edible items brought to class or lab must be thrown out.
• If student elects to eat/drink outside class or lab door, missed time is recorded as absent.
• Attendance is taken hourly. Tardiness or absence is recorded in 15-minute increments. If you MISS 3 CLASSES YOU WILL AUTOMATICALLY FAIL THIS COURSE.
• Break times are scheduled by the instructor at appropriate intervals.
• No private software is to be brought to lab or loaded onto school computers.
• No software games are allowed in lab (unless in course curriculum).
• Headphones are required if listening to music during lab. No headphones are allowed in lecture.
• Any student who has special needs that may affect his or her performance in this class is asked to identify his/her needs to the instructor in private by the end of the first day of class. Any resulting class performance problems that may arise for those who do not identify their needs will not receive any special grading considerations.

Disability Policy Statement:

It is our policy not to discriminate against qualified students with documented disabilities in its educational programs, activities, or services. If you have a disability-related need for adjustments or other accommodations in this class, contact the Disabilities Services Coordinator at 415-276-1060.

Academic Honesty Policy:

Students are expected to maintain the highest standards of academic honesty while pursuing their studies at AiCA-SF.  Academic dishonesty includes but is not limited to: plagiarism and cheating; misuse of academic resources or facilities; and misuse of computer software, data, equipment or networks. 

Student work that appears to violate AiCA-SF’s standards of academic honesty will be reviewed by the Committee on Academic Honesty.  If the work is judged to have violated standards of academic honesty, appropriate sanctions will be given.  Sanctions include but are not limited to course failure and academic termination.

Project 1: cup, apple and book scene - due week 3 - 15%

• unwrap each object and fit UVs into 0-1 space
• create color, bump and spec maps for each object (1024 minimum resolution)
• light scene with 3 point lighting and depth map shadows from main light
• render in Maya renderer (1280 x 720)
• zip and submit maya file, textures and rendered images.

Project 2: wall, tree and shield scene - due week 6 - 25%

• unwrap each object and fit UVs into 0-1 space
• create color, normal and spec maps for each object (1024 minimum resolution)
• light scene with mental ray physical sun and sky
• render in Mental Ray renderer (1280 x 720)
• zip and submit maya file, textures and rendered images.

Project 3: final project - original environment - due week 11 - 40%

• create an original environment using found and authored models.
• unwrap each object and fit UVs into 0-1 space
• create color, normal and spec maps for each object (1024 minimum resolution)
• light scene with mental ray physical sun and sky
• render in Mental Ray renderer (1280 x 720)
• zip and submit maya file, textures and rendered images.

Suggested Course Outline

Week 1:

Lecture: Introduction to mapping and materials, hypershade, photoshop pipeline, render settings.

Lab: Basic material exercise, unwrap chair uvs     

Homework: Complete the lab work. Unwrap and texture book, apple and coffee cup, and create color textures for each.

 

Week 2:

Lecture: Using lights and creating textures. Bump and spec maps – Critique

UV’s. How to create alphas.

Lab: Creating materials.      

Homework: Create bump and specular maps for 1st scene. Light scene and render out images.

 

Week 3:

Due: Project 1

Lecture: Procedural textures. Mixing procedurals with bitmaps. Intro to Mental Ray renderer. Painting textures in Maya.

Lab: texture editing

Homework: Light Unwrap wall, tree and shield scene, all objects. Create 1st pass color maps.
 

Week 4:

Lecture: Maya substance nodes. Physical sun and sky.

Lab: Create Substance nodes and phys sun/sky

Homework: Begin a color pass on the next scene given  
 

Week 5:

Lecture: Normal and displacement maps.

Lab: One on one help

Homework: Finish Project 2
 

Week 6:

Due: Project 2 due

Lecture: One on one critique and instruction

Lab: Work on the Library  

Homework: Finish texturing and lighting the library for next week

 

Week 7:

Lecture: Final project break down. Critique – libraries.  Vertex painting, using Mudbox

Making Photoshop custom brushes

Lab: conceptualize final projects, decide on group vs. individual

Homework: Start unwrapping and model editing scenes for the final  
 

Week 8:

Lecture: MIA, and MIA X materials in Maya – Using the hypershade for connections

Lab: Start placing things in the scenes and polish UV’s – start texturing

Homework: Light and texture Scenes  - Turing Week 9 progress
 

Week 9:

Lecture: Critique of group project  

Lab: Work on scenes

Homework: Work on the lighting  
 

Week 10

Lecture: Special lighting. GI -Global illumination. Image based Light    

Lab: Work on texturing and lights  

Homework: Work on your final project.    

Week 11:

Lecture: Project assessment, hand in your projects for evaluation     .

Lab: Turing in any redos  

Homework: None.