An introduction to ISL

[CTZn]

for them not too shy.

The purpose of this booklet is to lead the novice, supposedly impressed by the notion of coding, into a guided first contact with the Indigo Shading Language (ISL).

As such, the reader is expected to have been through UV texturing and is now willing to use a different method to define materials in Indigo.

From there, the tutorial will try to conceal the technicity that ISL may involve by proceeding from one illustrated step to another. Sometimes in an imaged language, often at the price of technical accuracy. Theoretical insights will happen when required.

It was funny but now I'm aiming at a more polished result, let's screw with the deadline

[aleksandera]

Lol, great!

[CTZn]

What's next:

1d noise, in U or V
noise01, a variant usefull in our case.
scaling of noise, with creation of an UI param control.
2d noise
stretched 2d noise

Then practical shading examples. Hopefully the level of complexity will be mainained at the lowest.

Obviously I meant to post in the tutorials forum *facepalm*

[wlf_alex]

Super !
Will waiting for..

[Voytech]

Been waiting for something like this but still getting lost without illustrations. Maybe a paragraph regarding the syntax would be helpful.

[CTZn]

Thanks for the input Voytech.

I'm directing this paper to people who want to start using ISL but believe that it is entirely above their head. So far the introduction hereby is to demonstrate the contrary.

I have deliberately ignored confusing stuff, like data types and procedures definitions with this particular audience in mind. It may not be satisfying to intermediate audiences but I owed a thing to start with.

You can expect an update within the next 24h, with illustrations to clarify. I mean to have finished the tutorial by the next week.

[CTZn]

In fact, my target audience is not even necessarily comfortable with the definition of UVs. I'm eluding explanations by a visual exposition of the parameters.

So I could put it this way: this first part already written is entirely meant to familiarize empirically the reader with the notion of U and V coordinates, by having him exposing them with ISL.

All it takes is replacing the value 0.1 by texi() - exposing U - or texj() - exposing V.

I want everybody into ISL, I'm on it

[LithiumDesign]

Think this is a fantastic idea - seeing as I am one of those people that was intimidated by ISL - but I don't really understand where I need to add the texi() part?!

[Voytech]

In fact, my target audience is not even necessarily comfortable with the definition of UVs. I'm eluding explanations by a visual exposition of the parameters.

So I could put it this way: this first part already written is entirely meant to familiarize empirically the reader with the notion of U and V coordinates, by having him exposing them with ISL.

All it takes is replacing the value 0.1 by texi() - exposing U - or texj() - exposing V.

I want everybody into ISL, I'm on it

Everything fine so far, until I input texj...... that causes indigo to crash instantly. Bug?

[CTZn]

Released update 1. Polished the spoiled french humour a bit, added images that will clarify.

Voytech, Indigo should not crash. If it worked with texi() just hilight the "i" and type a "j" instead. Let us know about this.

[OnoSendai]

Good stuff, I like the style

[wlf_alex]

Very useful, thanks !!!

[CTZn]

Great, thanks guys !

Update 2 is out.

Where the reader will apply a one dimensional noise to the surface, and scale it at will.

[Voytech]

The illustrations are what made it perfectly clear to me. Thanks. Keep going!

On a less happy note - Indigo crashes consistently when I use "texj()" in the syntax. It crashes as soon as I close the parenthesis. This is on IndigoRT 3.6.2 on OS X 10.8.2.

[CTZn]

texj() is a shortcut for e1( getTexCoords( 0 ) ) they are supposed to be interchangeable.

getTexCoords(0) -> first UV set
getTexCoords(1) -> second UV set
etc...

e1(getTexCoords(0)) -> second element of the first UV set. The first element (U aka texi()) is the element number zero: e0(getTexCoords(0)).

That's for a short explanation but honestly it seems more like an hardcoded bug. HopeFully Ono will catch it here or we will raise it where it belongs.

The illustrations are what made it perfectly clear to me. Thanks. Keep going!

I haven't done a thing today but I'm maintaining the schedule, the tutorial will be complete by the next week. That's very encouraging from you, thanks !