[comp.graphics] one plane lighting..

mcooper@sunb3.cs.uiuc.edu (08/25/90)

An interesting problems here.  One I've never encountered before.  Using 
an SGI PI, I was adding lighting to some code.  What appears to be happening is 
that the machine itself is ignoring (or setting to zero) any Z component of
any light.  

	Which is to say, if I specify a light as 

	front[] = {POSITION, 1.0, 0.0, 1.0, 0.0, LMNULL};

the machine treats it as:

	front[] = {POSITION, 1.0, 0.0, 0.0, 0.0, LMNULL};


You can see how this might get irrtating.  It IGNORES the default light!
Any light I put at any location outside the Z plain gets projected back
to it!


Any suggestions?


+-------------------------------------+----------------------------------------+
|  "When the going gets weird,        |                                        |
|              the weird turn pro."   |  Marc Cooper	mcooper@cs.uiuc.edu    |
|		  		      |  University of Illinois, C-U	       |
|		 -Hunter S. Thompson  |					       |
+-------------------------------------+----------------------------------------+