surfaceLuminance Node behavior query

Become a member of the CGSociety

Connect, Share, and Learn with our Large Growing CG Art Community. It's Free!

THREAD CLOSED
 
Thread Tools Search this Thread Display Modes
  11 November 2003
Question surfaceLuminance Node behavior query

I am trying to create a relatively simple shader network in Maya that will shade a simple sphere with a dynamically changing Earth shader, one half daylight and one half night. The night texture has all of the city lights visible but no real colour information.

I am using a Layered Shader with two layers, one for the night and one for the day. The night layer has a Ramp (mapped to V) with a surfaceLuminance node connected to the V value, the ramp is then connected to the Transparency attribute of the night earth shader. This should work in theory.

However in practice it doesn't seem to want to, I am not quite sure why. Can anyone suggest why this strange effect is happening?

 
  11 November 2003
If I am to guess, I'd say that the luminance in the circular region of error is going beyond 1.0, and your shader can't handle it. I'll bet your ramp is going to 0.0 when the v-index goes past 1.0.

I don't know a solution off-hand, though I've dealt with this problem in the past... Some things to try perhaps:
- play with "Default Color" on ramp?
- multiply the output of surfaceLuminance by a factor?
- adjust (lessen) light intensity?
- play with 2d texture placement settings?

Something will work...

- Matthew Durante
 
  11 November 2003
hi,

You could use a blendColor and a surfaceShader instead a layerShader.
Connect the surfaceLum to a setRange and set the Xvalues (oldMin, oldMax min and max to 0 and 1 to avoid the result looping (what you have done with your ramp))
Connect then the setRange.outValueX to the blender.

In the color1 connect your daylight texture/shader and color2 your night shader.

Create then a surfaceShader and connect the blender to it, then assign the surfaceShader to your sphere.

Et voila


Emmanuel
__________________
Emmanuel Campin
Infographiste 3d - Maya
www.pixho.com
pixho@pixho.com
 
  01 January 2006
Thread automatically closed

This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.
__________________
CGTalk Policy/Legalities
Note that as CGTalk Members, you agree to the terms and conditions of using this website.
 
Thread Closed share thread



Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
CGSociety
Society of Digital Artists
www.cgsociety.org

Powered by vBulletin
Copyright 2000 - 2006,
Jelsoft Enterprises Ltd.
Minimize Ads
Forum Jump
Miscellaneous

All times are GMT. The time now is 01:03 PM.


Powered by vBulletin
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.