Utilisation : Les liens ne sont pas apparents. Pour obtenir des informations sur un mot clé, cliquez-le dans le script !

// Persistence of Vision Raytracer Version 3.5 Scene Description File
// File: math.pov
// Last updated: 9. Sept. 2001
// Authors: Chris Huff / Bob Hughes / Tor Olav Kristensen
// Description: Graphing of functions
//***********************************

#version 3.5;
#include "stdinc.inc"

//-----------------------------------

global_settings {assumed_gamma 1}
#default {finish {ambient 1 diffuse 0}}

//-----------------------------------

// Which graph to show.
// 0 for power, 1 for trig, 2 for inverse trig, 3 for various
#declare Graphic = 3;

// The aspect ratio of the image.
// (To get equal thickness of vertical and horizontal lines.)
// E.g.: 800/600 = 4/3, 320/200 = 8/5
#declare AspectRatio = 4/3;

#declare vAR = <AspectRatio, 1>;

// Set to true to get a border. S L O W.
#declare Border = false;

// Half of the "thickness" of the lines
#declare CylRadius = 0.006;

//-----------------------------------

#macro v2Dto3D(v0)
	<v0.u, v0.v, 0>
#end	// macro v2Dto3D

#macro vNorm(v0)
	#local pGraphCtr = (pGraphMax + pGraphMin)/2;
	#local vA = (v0 - pGraphCtr)/(pGraphMax - pGraphMin);
	(vA*vAR)
#end	// macro vNorm

#macro PlotPoint(p0)
	sphere {v2Dto3D(vNorm(p0)), CylRadius}
#end	// macro PlotPoint

#macro PlotLine(p0, p1)
	cylinder {v2Dto3D(vNorm(p0)), v2Dto3D(vNorm(p1)), CylRadius}
#end	// macro PlotLine

#macro Graph(Func, Num, Color)
	union {
		#local X = pGraphMin.u;
		#local pLast = <X, Func(X)>;
		PlotPoint(pLast)
		#local Xstep = (pGraphMax.u - pGraphMin.u)/(Num - 1);
		#local J = 1;
		#while(J < Num)
			#local X = X + Xstep;
			#local pNext = <X, Func(X)>;
			PlotLine(pLast, pNext)
			PlotPoint(pNext)
			#local pLast = pNext;
			#local J = J + 1;
		#end
		#if (Border)
			clipped_by {
				box {
					-<0.5, 0.5, CylRadius>,
					<0.5, 0.5, CylRadius>
					scale vAR + z
				}
			}
		#end	// if
		pigment {color Color}
	}
#end	// macro Graph

#macro GraphSetup()
	// Coordinate grid
	box {
		-<1, 1, 0>, <1, 1, 1>
		scale v2Dto3D(vAR)/2 + z/10000
		texture {
			pigment {checker color Gray20, color White}
			scale v2Dto3D(GraphScale*(vNorm(<1, 1>) - vNorm(<0, 0>))) + z
			translate v2Dto3D(vNorm(<0, 0>))
		}
	}
	// X-axis
	object {
		PlotLine(pGraphMin*u, pGraphMax*u)
		pigment {color Black}
	}
	// Y-axis
	object {
		PlotLine(pGraphMin*v, pGraphMax*v)
		pigment {color Black}
	}
	camera {
		orthographic
		right x
		up y
		scale v2Dto3D(vAR)*(Border ? 1.08 : 1) + z
		location -z
		look_at <0, 0, 0>
	}
	#if (Border)
		background {color Gray10 + Blue/2}
	#end	// if
#end	// macro GraphSetup

//-----------------------------------

#switch(Graphic)
	#case(0)	// power functions (^ operator)
		#declare pGraphMin = <-5,-5>;
		#declare pGraphMax = <5, 5>;
		#declare GraphScale = <1, 1>;
		Graph(function(x) {x}, 300, Red)
		Graph(function(x) {x*x}, 300, Green)
		Graph(function(x) {x*x*x}, 300, Blue)
	#break
	#case(1)	// trigonometric functions
		#declare pGraphMin = <-90,-1.5>;
		#declare pGraphMax = <270, 1.5>;
		#declare GraphScale = <10, 0.1>;
		Graph(function(x) {sind(x)}, 300, Red)
		Graph(function(x) {cosd(x)}, 300, Green)
		Graph(function(x) {tand(x)}, 300, Blue)
	#break
	#case(2)	// inverse trigonometric functions
		#declare pGraphMin = <-1,-180>;
		#declare pGraphMax = <1, 180>;
		#declare GraphScale = <0.1, 10>;
		Graph(function(x) {asind(x)}, 300, Red)
		Graph(function(x) {acosd(x)}, 300, Green)
		Graph(function(x) {atan2d(x, 1)}, 300, Blue)
	#break
	#case(3)	// various functions
		#declare pGraphMin = <-10,-10>;
		#declare pGraphMax = <10, 10>;
		#declare GraphScale = <1, 1>;
		Graph(function(x) {sgn(x)}, 300, Red)
		Graph(function(x) {clip(x,-3, 2)}, 300, Green)
		Graph(function(x) {clamp(x,-3, 2) + 0.001}, 300, Blue)	// +0.001 to make it visible beside clip()
		Graph(function(x) {adj_range(x, 3, 5)}, 300, Yellow)
		Graph(function(x) {adj_range2(x,-3, 2, 3, 5)}, 300, Orange)
	#break
#end

GraphSetup()

Et voici ce que nous obtenons :