4.2 - Blender

Blender is a combination of many tools. It is a:

For this textbook you only need to learn how to use the modeling functionality of Blender. Please don’t even try to “master” all of the functionality of Blender. It takes years to become a Blender “power user”.

To understand the power of Blender, sample some of the animations posted on this youtube play list, all of which were created entirely using Blender.

Install Blender

Please install Blender on your computer. Download Blender from here.

IMPORTANT

To use Blender effectively, you need to use a 3-button mouse. If your mouse has 2-buttons and a wheel, the wheel often acts as a 3rd button.

Some Preliminary Issues

Blender uses a right-handed coordinate system, but a different default view orientation as compared to WebGL.

  • In Blender, the ground plane is the X-Y plane and the Z axis points up.
  • In WebGL, the ground plane is the X-Z plane and the Y axis points up.

This discrepancy in default views can cause confusion, but the difference is only a 90 degree rotation about the X axis. In the WebGL program below, the x, y, z, axes are rendered as red, green, and blue arrows respectively. In addition, the front, right, and top views are labeled. Rotate the model down by 90 degrees and you will have the default WebGL 3D orientation, where the z-axis is pointing toward you and the y-axis is up.

Show the orientation of the sides of an object as viewed by Blender.
Please use a browser that supports "canvas"
Animate


Open this webgl demo program in a new tab or window

To minimize confusion we suggest that you use the default view in Blender as you design your models. Let the “front side” of your object be facing away from the +Y axis and the “top side” of your object be along the +z-axis. When you export your model, the exporter can change the orientation to match WebGL’s orientation. (More details on this are in the next lesson.)

When you create models for WebGL programs you can save multiple models in a single file, or separate the models into distinct files. If your models are in separate files, make sure you use consistent units so that your models have an appropriate size when they are used together in a scene.

Every model requires a unique name so that it can be manipulated in your WebGL programs. Use the normal rules for creating program identifiers to name your models – because model names will become object property names in your WebGL JavaScript programs.

IMPORTANT

When naming things in Blender, such as models, colors, or textures, all names should start with a letter (a-z) and contain only letters (a-z), digits (0-9) and the underscore character (_). Never use spaces in your names!

Learning Blender

Please watch the Blender video tutorials by Neal Hirsig listed below. Your goal is to learn WebGL programming, so you don’t need to watch all of his Blender videos. Just learn from the subset of videos listed below.

IMPORTANT

You should watch a small part of a video, pause the video, and then practice the actions described by the video. Practice and experimentation are critical to your learning.

Please print a copy of the Neal Hirsig cheat sheet to have in front of you as you watch the tutorials. As you learn each new functionality, it will be helpful if you makes notes to yourself on the cheat sheet.

Learn the Blender interface (34 minutes of video):

Learn model manipulation in Blender (43 minutes of video):

Learn advanced model manipulation in Blender (39 minutes of video):

Learn mesh editing techniques in Blender (49 minutes of video):

Putting it all together (9 minutes of video)

Other Resources

There are many great video tutorials on the Internet that can help you learn Blender. The Blender Foundation tutorials is a good place to start. Just recognize that it will take you 100’s of hours to master Blender and any extra work in Blender should be put off until after your work on this WebGL textbook is finished.

This extensive cheat sheet will be helpful if you want to learn more about Blender.

Glossary

Blender
an open-source, free modeling and animation tool.

Self-Assessment

Using Blender, create a model of some simple 3D object. Be creative, but don’t make it too complex.

Next Section - 4.3 - OBJ Data Format