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bunnyld

01-05-2007, 05:15 PM

hey all

I have some questions about color in mental ray ... hope you can help me out =)

OK as far as i know (please correct me if i'm makin a mistake):

red plastic is red because it take all the colors of the light and return red only.

in LW diffuse was the amount of light that the object will return to the camera out of the 100% light intensity that existent in the scene.

the color was just color.

now when i'm going to XSI interface and using phong shader, i can see diffuse and ambient.

- what is the meaning of diffuse and ambient when using mental ray on XSI?

- what shader will be best to start with, when creating cup of tea made of porcelain

thanks =) !

RenisanceX

01-05-2007, 06:30 PM

lw_color=mental diffuse
Lw diffuse= mental ambient

Felipe

01-05-2007, 07:02 PM

lw_color=mental diffuse
Lw diffuse= mental ambient

lw diffuse is not the same thing as mental ambient. There is no equivalent in mentalray phong shader to lw diffuse by default, altough it is easy to set it up using render tree.

Felipe

CiaranM

01-05-2007, 07:16 PM

lw_color=mental diffuse
Lw diffuse= mental ambient

In lightwave (and Maya) diffuse is simply a multiplier of the surface colour on an illuminated surface. This is different from the ambient in XSI, which adds to the surface values, irrespective of illumination. Ambient in XSI is additive to the diffuse value, whilst the 'diffuse' of LW is a multiplier of colour. I'm pretty sure LW has an ambient or luminace variable.

Diffuse in XSI is not so different from LW or Maya, the two variables of colour and intensity (LW diffuse) are controlled simultaneously.

Just think of your XSI 'diffuse' as colour x diffuse. And since it is just a multiplier, you have control of each value, just as you would in LW, but by using a combination of input nodes.
You will have a better grasp if you use HSV units in you colour picker

bunnyld

01-06-2007, 03:17 PM

thanks to all

playing with the colors, and incidence map i have done this material

it's a phong shader

what is the right way to creat that kind of shder?

http://www.cgtalk.co.il/forum/files/cup_cheker4.jpg

norvman

01-08-2007, 01:22 PM

playing with the colors, and incidence map i have done this material
it's a phong shader
what is the right way to creat that kind of shder?

I'm a little confused.... you did this in Wave or in XSI?

:shrug:

norvman

01-08-2007, 02:23 PM

heres a bit of stuff here...

http://www.xsibase.com/forum/index.php?board=12;action=display;threadid=9835

CiaranM

01-08-2007, 03:10 PM

This thread would make useful reading, also:

http://forums.cgsociety.org/showthread.php?t=410205

bunnyld

01-09-2007, 05:13 PM

Did this in XSI

don't use LW any more

thanks for the links

norvman

01-09-2007, 05:24 PM

don't use LW any more

Ditto... :thumbsup:

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