   urgent problem with gouraud shading, plz help
  Hi there got a problem with calculating the appropriate color for a point inside a gouraud shaded triangle...am a Noob with graphics lolBasically because of how we do things i cant use the scan line approach as im given a point that once i figure out what triangle its in must calculate its color based on the colors at the vertices of the triangle.Now i dunno if its just me but i am finding it very hard to find details on how this is done, wherever i look they seem to be glossed over.This is my understanding am i correct or not?given a triangle, with vertices a,b and c and colors at these points of c1,c2,c3   a -----b------cif i want to know the ratio of c1 at a point inside the triangle, call it d, draw a line from a through d (ad) and now extend it till it intersects with the the side opposite a ie: bc and call this intersection point e.now i just do   size(ad)/size(ae) to get the ratio i should apply to d of c1 (ie the colour at a).i would then repeat for each vertex and add and average the rgb values ie:r = ratio(colour at d) = c1*r + c2*r2 + c3*r3Is this the way to do this or no ?????? Azure ps: urgent cause is work related and i leave in like 3-4 days and wouldnt want leave em with my incomprehensible code withought it working lol :)   
  Check out barycentric coordinates. They solve exactly this problem.   ;  Ty v much that helps with establishing the ratios from each vertex, but is what im saying correct about how to use those ratios to determine the colour to be applied for gouraud shading? does gouraud shading use barycentric co-ords to determine colours???ie:(colour at d) = c1*r + c2*r2 + c3*r3   ;  ive found what i was looking for athttp://www.devmaster.net/articles/software-rendering/part4.php