This is an exciting one. Let me show you the journey down. 😉
Remember what Lee, Daniel and I did back in the end of 2012? To refresh your memory, here is what happened.
- Freestyle wasn’t in Blender yet.
- Blender NPR just started.
- We made Edge nodes.
Yes, the pre-freestyle line art era. Edge nodes took us about one month to publish. In that one month I saw the full potential of learning pixel math. It was way too cool to put into words. Let’s see some images.
The table line art render above cannot be done properly with Freestyle. As someone who wrote a comprehensive Freestyle course, trust me, freestyle cannot produce better line art compared to pixel math. Pixel math’s quality is almost hand drawn. To get this render, everything is done in pixel math via the compositor.
The power of pixel math isn’t limited only to the compositor. You can use it in material node as well.
A popular understanding is that you need to plug images into both inputs of mix node. Yet you don’t have to. You can drive the color mixing using only grey value inserted into factor input.
Yes, yes, I can hear some voices saying: “Nice render sir, but mix node is simple.”
No. Mix node is not simple. It is not too hard either. Mix node is just not explored and exploit to its full potential. Plus a lot of artist only understand few blend types, they are:
But what about the awesome Burn and Dodge blend modes? Do you know that the Soft Light blend mode is way better than Overlay blend mode? Do you know that Overlay has Multiply algorithm in it?
We are traversing too deep too soon, let’s back up a little. 😀
Let’s go back to Mix node. The Mix node that we use now is in RGB. We actually can make Mix blend mode in HSV.
Do you know that mix blending algorithm is in almost all blend mode available in Blender? Only one blend algorithm is without the Mix algorithms which is Dodge blend mode. Another note, mix algorithm looks different in other blend modes. Thus almost everything is a remix of the Mix blend mode.
Other than the cult like node hacking, blend modes are very fun as well. For example we can use the Difference blend mode to solve spot the differences puzzle.
Note: Pixel Math is not limited to non-photorealistic application. It is heavily used in VFX & motion graphics.
As you might have noticed by now, pixel math can be applied extensively (Edge node below) or sparsely (material node example above).
Pixel Math (noun): Mathematical equations & algorithms which determine color behavior when two or more colors are layered on the same pixel location. Commonly known as blend modes.
If there is a way to learn pixel math, then it is first through the understanding of the basic blend algorithms provided via Mix node. After that, you can pick your own path. Solve some compositing problems. Invent new solutions to old problems. Take different point of view or a new paradigm to solve them. That’s where my Pixel Math e-book comes into the picture.
Up until now, blend modes are not well documented. The descriptions are often too vague. Without knowing the algorithms that produced them, we can’t say for certain that,
“this color blends that color, at that factor value, will resulting in that final color.”
My Pixel Math journey has been like this:
The e-book shows the top of the iceberg (describe the blend modes in easy to understand terms), opens your eyes to common blend algorithms (extracted directly from Blender source code) and invites you to make your own from what you have learned (the journey to the abyss).
I can say for certain that the people who have read the e-book will say this to you:
“You must be mad for not knowing pixel math deeper and earlier.
Almost everything you do in Blender involved pixel math.”
And just last week (week of June 14th 2015), 1 artist told me:
“Oh yeah, I think you’re touching on some shit I’ve been ranting about forever.”
After seeing the e-book, he was venting how come there were so little information about something so essential before the e-book. Yet he was not the first person telling me that last week. In fact he was the 3rd person.
As a digital artist, this is an important book. A Must Get.
You can get Pixel Math e-book via Blender NPR Store.