s t    c o l o r a t i o n


These images show the results of using the RenderMan Shading Language (RSL) to write a variety of special effects surface shaders. The notes and RSL code accompanying each image explain how each effect was achieved.





Cross. With fading red to yellow colors. As with other examples here you will see that
I had to implement several mathematical forumalas... of which I hate and dread. 

			

			

if((s > .25 && s < .75) || (t > .25 && t < .75))
surfcolor = color(1,s,-s);
			




			

			

if (s >= 1-t) 
surfcolor = color(1,s,-s);
	
			




			

			

if((s > .25 && s < .75) || (t > .25 && t < .75))
surfcolor = color(1,s,-s);




I used two circles here and moved one slightly to the right, and colored it as the same
color as the square. 

			

			

if(((s-.5)*(s-.5))+((t-.5)*(t-.5))<.2) 
	surfcolor = color(1,s,-s);

if(((s-.4)*(s-.4))+((t-.5)*(t-.5))<.2) 
	surfcolor = color(.4,.4,.4);




In this design I started with a diagonal and overlaped additional smaller diagonals on top
of it and in alternating colors to get the stripes. I then repeated this technique in the
other direction. I then placed two circles in the center. One cuts out part of the blue and
leaves the red, while a smaller circle acts as a small black hole in the center. 

if (s+1 >= 1-t) 
surfcolor = color(0,0,1);

if (s+.8 >= 1-t) 
surfcolor = color(s,0,0);

if (s+.6 >= 1-t) 
surfcolor = color(0,0,1);

if (s+.4 >= 1-t) 
surfcolor = color(s,0,0);

if (s+.1 >= 1-t) 
surfcolor = color(0,0,1);

if (s >= 1-t) 
surfcolor = color(0,0,1);

if (s-.1 >= 1-t) 
surfcolor = color(s,0,0);

if (s-.4 >= 1-t) 
surfcolor = color(0,0,1);

if (s-.6 >= 1-t) 
surfcolor = color(s,0,0);

if (s-.8 >= 1-t) 
surfcolor = color(0,0,1);

if (s-1 >= 1-t) 
surfcolor = color(s,0,0);

if(((s-.5)*(s-.5))+((t-.5)*(t-.5))<.03) 
	surfcolor = color(s,0,0);

if(((s-.5)*(s-.5))+((t-.5)*(t-.5))<.01) 
	surfcolor = color(0,0,0);