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digiralph
04-20-2003, 01:05 PM
Hi everbody,
I'm a student studying in graphic communiaction :) . I am now trying my best to learn rendering on my own. And I do have some questions:
- What is the different between the shader wrote in renderman and shader made in Hypershade of Maya?
- Is there any good reference or tutorials online about writing shader in renderman?

Best regards,
digiralph

Wess
04-20-2003, 04:00 PM
HI.

Writing shaders in renderman is like scripting a small program. That means u need to have some basic programming skills and know the shader language which is C-like for ur renderer.

Plugging shading network is about setting relationships between attributes of different nodes. Usually they are the nodes that u can create in hypershade. You can do shading network without any programming background but you may have to know some simple math for more complex network.

An option would be MTOR (Maya TO Renderman), it has a bunge of nodes for u to plug and play to create renderman shaders within maya.

Where are u studying at in HK? PolyU?

Wesley :bounce:

digiralph
04-21-2003, 09:12 AM
Hi Wess,

Thank you for your reply.
I am studying in HKBU - DGC. You know HK?
And i want to know what is the different in the outcome of both shaders? I know that the size will be smaller in "writen-shader" that in the "linked-shader".
So it is the same principle that write function in JavaScript on our own (write shader in SL) is more concise than use function provided by Dreamweaver (link shader in Maya)?
Thanks again!:applause:

Wess
04-21-2003, 10:11 AM
HI, i'm a hk guy in hk!

I know 0 about those web things,........ :thumbsdow

First, i actually feel comparing prman shading language with maya's hypershade isn't that appropriate....

To write ur own shader or do it by plugging a shading network can sometimes give u the same results (I'd say usually when things are relatively simple). For example, I want a checker shader. If u do it by hand writing, u will need probably 10 lines or so. If u do it by maya shading network, u need a few clicks. (Of course, the network u can create in maya can do much more than just checker, ramp, fractal,...) It sounds that the network is more handy, right?

But, there are also times that u want to write a shader. Let's say u need the shader to do recursive things by loops, selections by conditions, things with some more math, or things which are more complicate as a whole...etc; it would be much easier by scripting the codes. In maya, u can write expressions in the expression editor, and it can work with the hypershade to do some nice things. Attributes u called in the expressions will be automatically setup in the hypershade by a expression node.

The approach to ur shader really depends on what u want to do. In the world of shader writing, i am still just a newbie...but i hope my words here can help u a bit.

Welcome to the fasinating world of CG!!

Wesley

digiralph
04-21-2003, 10:52 AM
Thanks a lot, Wesley! :thumbsup:

I am really happy that i can meet local people here!!!
Actually i just start learning writing shader by reading books so i lack some real practises. And you really help and encourage me a lot!

Besides, are you a working people or a student?

Happy Easter Holiday!!!

digiralph

Nicool
04-23-2003, 12:25 PM
There is a great tutorial about SL writing on www.deathfall.com

Fex
04-24-2003, 11:19 AM
hi

if you want to get deep in shading and lightning writing own shaders is also good for getting a general knowledge of
thinks work exactly... e.g. how specular light is generated

best book about SL:
Advanced RenderMan by Larry Gritz

SL links:
http://www.accad.ohio-state.edu/~smay/RManNotes/rmannotes.html

http://www.renderman.org/RMR/OtherLinks/index.html
:)

digiralph
04-29-2003, 06:45 AM
thanks Nicool and Fex

Fex,
Yeah, Advanced RenderMan is really a great book!!
but i want to know if "Essential RenderMan Fast " by Ian Stephenson is helpful for beginers?

Again, thanks very much!!!

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