Function of the "Functions"

[dhavalmistry]

I was wondering if you experts could provide me with some of your expertise on function shaders...meaning how they work and hpw to get them work....

[Rich]

i really dont know much and dont want to sound too dumb but since no one else is replying why not...
first of all you should go to the tutorials and look at the one on building terrain from functions...
then try changing up what the functions in it are, and add some more to see what happens, thats what i did and ive learned a bit doing that...
other than that, many of them do just what they say they do, like multiply, divide, square root etc,, and its where you put them in the order of the node that matters, so that it actually affects some part of the terrain that you know the function of, like a power fractal shader...

[dhavalmistry]

man...finally someone is kind enough to share their knowledge on function shaders....

just joking.....can you direct me to the tutorials please

thanx rich....

[Will]

Yea I don't know much about them either but you should try looking in the Documentation section they have a little bit in there as well as just trying search there has to be somthing here.

Regards,

Will

[Rich]

http://forums.planetside.co.uk/index.php?topic=195

[Will]

Nice find

[BPauba]

I am afraid I cannot be much help, because I am learning them as well! Like Rich said, alot of them work in the way a equation would work, and if you can properly place them in the node network they do create some interesting effects, but I have not gotten to that yet lol.

[king_tiger_666]

that tutorial is good i must say after following it. but it really only uses 3 or 4 functional nodes and doesn't really go into much depth of how they work. though some people have done entire functional terrain renders and posted them here.. might be worth a search to see if they have shared their files you can have a  look at..

[groverwa]

Gday

Have a look at http://forums.planetside.co.uk/index.php?topic=733.msg6208#msg6208 where I have had a play with a tgd from Dave Burnett

Mike

[Oshyan]

The Functions work just like any other nodes, for the most part. Understanding how the various mathematical operators actually work is well outside the scope of a short forum explanation. There are entire books devoted to writing shaders for systems like Renderman. This is similar, although the range of functions is lesser at this point (it will be expanded in the future).

I think the best piece of simple advice is if you don't understand the math behind a given function, you either need a lot of patience and persistence to experiment and find out what it does, or you should just leave them to those that more deeply understand what's going on. I will certainly confess that I have barely a clue how to get anything useful out of the function nodes. Certainly don't make the mistake of thinking they're necessary for getting many effects. In fact very few images thus far have used function nodes and we've seen some pretty amazing things already.

Eventually the function nodes will be covered in a full Node Reference, which is still very much in progress over in the Documentation section. But you can imagine how much time it will take to explain them all, so this will be a little while in coming.

- Oshyan

[Ironshirt]

http://www.imaginary2008.de/surfer.php

This is a link to a program called surfer. It is a program to visualize real, algebraic geometry in realtime.
I think it will be very useful for me (and perhaps for others as well) because I'm not very familiar with functions in TG2.
By now I followed the trial and error method to create geometry with functions in TG2.
With surfer we now have the possibility to test functions and their visual results before trying them in TG2.
I just found the program several hours ago and while I'm still at work I had no chance to do a test, if the function I created with surfer, also works in Tg2. But I guess it should. Will try it later when I'm at home...

Regards,
Michael

[Virex]

What i currently understand of the nodes is that they take their input and do what they say with that. So if you put a scalar into a sine, it's output will be equall to the sine of the input. Same with power. If you raise a colour to a power, then each component of the colour will be raised to that power. I'm not exactly sure what happens when you raise a colour to a power, but since it get's darker i'm guessing it treats every component as if it were a number between 0 and 1.

Btw, the small preview window on the left of the main preview windo will show you the output of your function for every point. It only ranges from black (0) to white (1) though, and it's flat, so it's not always very usefull. Still, it gives you an idea of what your functions are doing.
If you look at the output of a vector, you'll see that there are 4 squares. That is because each component of the vector is treated as a different colour.

[Mr_Lamppost]

This series of four tutorials, also in the documentation section unlocked the "little blue boxes" for me    Of the four I found the third useful not because it explains how any actual nodes work, it doesn't but because it shows the way to work with function generated terrains.

http://forums.planetside.co.uk/index.php?topic=1166

http://forums.planetside.co.uk/index.php?topic=1167

http://forums.planetside.co.uk/index.php?topic=1168

http://forums.planetside.co.uk/index.php?topic=1169

[David Burnett]

Nice to see my old tutorials still come in handy :-)

For further information they were originally posted in the file sharing forum here...
http://forums.planetside.co.uk/index.php?topic=843.0
Which includes some discussion along side the tutorials

They were designed to extend my original functions guess work in this tutorial
http://forums.planetside.co.uk/index.php?topic=195