Chapter 7, Episode I

Chapter 7, Surfacing

Part Episode I, Basic Materials and Procedural Textures

If at this point you’re thinking, “Gee, I have to think about this kind of stuff for every object in my scene?” rest assured. The truth is that you don’t have to think about it that hard, if you want your work to be lame.

Wow, looots of information and this is just the beginning of the chapter. This post will be very useful for me to synthesize some things, hopefully you’ll find it useful too.

The author starts out by giving out general pointers to achieve believability in our scenes. The emphasis is on subtlety. Resist the temptation to overdo things, and carefully observe the environment to figure out how and why real things look the way they do.

Then it really pays off to know your tools, which are better to achieve what. If you’re like me you didn’t really go to the wiki documentation to figure out how different the shaders like Lambert or Minnaert really were. Well they are pretty different, and you will get better results in your images if you use the right thing. To help me remember the best uses for each, without having to open the book everytime I need to check them, I came up with the worst of mnemonics:

  • Oren-Nayer: NOn-glossy surfaces;
  • Lambert: mbertallic stuff, shiny, and shiny plastics too;
  • Minnaert: lush fabrics, by exclusion :P

Ready for something immensely useful? Here goes: he shares a list of material reflectance values in the real world, originally compiled in a post on the cgarchitect.com forums. You’ll be using that a lot. You see, nothing out there reflects 100% of the light it receives, so use this list as a guide for using the Diffuse Intensity control in your materials. Then he goes on to explain color and specularity (yep, it does need explaining); quick tips is to watch your color saturation (don’t overdo it, use real objects as reference), and to take out specularity entirely except when the object really has gloss and shine (again, check your references).  In terms of shaders, use Blinn when there’s no or low gloss (which is to say most often), and Phong or Cook-Torr for high-gloss. This is just a taste, the section is just chock-full of little tips, this alone is more than worth the book’s price.

We then start covering procedural textures. The web bucket has an incredibly useful video reference where Roland explains the different types of Noise Basis and their best applications. Then he explains the difference between UV and Generated coordinate mapping. Very basically, it goes like this: if the texture is something superficial, like a tatoo, UV mapping applies; if however it’s supposed to go the whole way through the object, like the rings in wood, we’re talking Generated mapping. Another great piece of expertise to remember: when you’re texturing, there are at least three layers you should apply: one that affects the Diffuse Color, another for the Specular Intensity and another for the Geometry Normal. When you do this though, always remember to subtract this influence to the respective base value of the material, so for example if you added a texture that affects the specular intensity of the material, go back to the material and subtract that value to its specular intensity. Again, the amount of other tips in the book is just enormous.

By the end of it, I had textures applied to my walls. Things are starting to look believable!

Kept the original resolution for detail (don't worry, the floor will be carpeted, try to ignore it)

Next up we’ll be adding more texture layers and exploring extremely basic UV mapping. This chapter is long, the longest in the book I believe, so this post series will have have six Parts. Actually… no. It’ll have six EPISODES, just like Star Wars. Yeeeeah! I’ve already told you what comes up in Episode II, then comes fast unwrapping in Episode III, advanced unwrapping and projection painting in Episode IV, texture painting in Episode V and camera projection in Episode VI. Much to learn we still have!

———-

This post is part of a series on the book Blender Foundations.
You can find the base post of the series here.

Next post on the series: Chapter 7 (Surfacing), Episode II
Previous post on the series: Chapter 6 (Character Creation), Part III

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6 responses to “Chapter 7, Episode I

  1. Moonwolf12 March 15, 2011 at 3:48 pm

    Those look just like my walls! I love how believable we can make things in Blender!
    I used clouds to make the pattern, along with negative normals.

    • Fax March 15, 2011 at 9:53 pm

      That’s pretty much it, but… why negative? Also, remember the specular channel! :)

      • Moonwolf12 March 16, 2011 at 2:27 am

        I forget XD the past few weeks I’ve been messing with textures, and in a project I needed to use negative normals to duplicate a texture, and I’m still learning about that!

      • Moonwolf12 March 16, 2011 at 10:50 pm

        I looked back at all my blend files, and I used negative normals to invert the normals, so that rust would look like it was eating at the walls, and not the other way around.

  2. Fax March 16, 2011 at 10:58 pm

    Ah, I see. The effect here is the opposite, the small bumps you get from painting a wall, either because of the wall’s roughness or tiny air bubbles.

    • moonwolf12 April 2, 2011 at 11:53 pm

      Exactly! You should try adding more than one texture because the bumpiness is random, and that looks a bit uniform. Or try a mask.

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