HDR Image-Based Lighting in Blender by Gleb Alexandrov

Gleb’s new training series is here! And it’s ‘freemium’, meaning you can pay whatever you want, including getting it for free!

Free tutorials by Gleb. Yay. I gave 10 bucks because I want him to drink coffee and never to quit blending :smiley:

Gleb Alexandrov make it look like it’s so simple!
Very good videos!

Ok, I’d like to ask a honest opinion to everyone who wants to share their educational experience with these videos.
Nothing behind it, no polemics, no flame, no dark meanings, no cospiracy theories, no illuminati things etc…
Just curiosity so don’t break my balls with idiocies.
If you want to share, do it. If dont, just ignore this post.

Have you found those tutorials useful for you?
What have you learned that you didn’t already know?

Useful? Very very much. So many tips and tricks that will make your work so much better. Gleb is a master when it comes to creative lightning.

I recommend that you watch it. The first 2-3 videos is more theory for beginners but the other learned me many things I could not think of doing.

In video #4 Image-based Lighting Workflow at 32:39 he says:

Under the hood some interesting math happens. Colours are getting multiplied by themselves in a non-linear fashion.
Dafuq is he talking about there? :confused:

Nothing really interesting.
Power is a non linear function by definition.

For those of you who don’t know what’s a generic linear function:
f(x)= ax+b
where f(x)=output value
x = input value
a and b are coefficents, their values depends by the situation.
Linear functions are represented by a straight line in a graph.

Here’s the basic code for the ASC-CDL node

Code Explaination:
take the input value (in), multiply by the slope value and add offset, call it “x”
then (in the return part) take the previous calculated value (x) and multiply by itself “power” value times.
return as output the result.

As said it sounds like a wisdom but it’s nothing really fancy.

The “by themselves” part still makes no sense to me.

power(n) function = multiply input by itself n times.
Examples:
3^2 = 33 =9;
2^4 = 2
222 = 16;
5^8 = 5555555*5 = 390625;

x^n = xxxxx… (n times)

It takes a pixel’s value as input, it makes a power function, it returns the new values for each pixel.

Right, that clears things up.
I suppose I was confused by the term “non-linear” here since I interpreted it as Gleb suggesting there’d be some gamma applied to the value before the multiplication. If he was merely referring to the power function in the color balance operation, that makes more sense.

Cheers. :slight_smile:

Thanks a lot. Very good video.

I’m a great fan of Gleb’s work, indeed there is generally only few things that I learn technically watching his videos, but I like very much how he cheat to get a nice result. It’s more a daily inspiration to me rather than new hot stuff to learn.
I guess for beginners that can be even more inspiring. Even if I found some stuff not to be best practice in a production environment, it’s good to think about all the possible ways to get a nice picture.
There isn’t much examples online about cheating, generally it’s about doing things the right way, but it’s good to learn a few shortcuts too.

People like Gleb make this world spinning… He is such a nice dude.

Thanks