1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
|
<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE html
PUBLIC "-//W3C//DTD XHTML 1.1 plus MathML 2.0//EN" "http://www.w3.org/TR/MathML2/dtd/xhtml-math11-f.dtd">
<html
xmlns="http://www.w3.org/1999/xhtml"
xmlns:mml="http://www.w3.org/1998/Math/MathML"
><head><title>gluLookAt</title><link rel="stylesheet" href="style.css" type="text/css"/><meta name="generator" content="DocBook XSL Stylesheets V1.59.1"/><link rel="home" href="index.xml" title="PyOpenGL 2.0.1.07 Man Pages"/><link rel="up" href="reference-GLU.xml" title="GLU"/><link rel="previous" href="gluLoadSamplingMatrices.3G.xml" title="gluLoadSamplingMatrices"/><link rel="next" href="gluNewNurbsRenderer.3G.xml" title="gluNewNurbsRenderer"/></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">gluLookAt</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="gluLoadSamplingMatrices.3G.xml">Prev</a></td><th width="60%" align="center">GLU</th><td width="20%" align="right"><a accesskey="n" href="gluNewNurbsRenderer.3G.xml">Next</a></td></tr></table><hr/></div><div class="refentry" lang="en"><a name="gluLookAt.3G"/><div class="titlepage"/><div class="refnamediv"><a name="gluLookAt.3G-name"/><h2>Name</h2><p>gluLookAt — define a viewing transformation</p></div><div class="refsynopsisdiv"><a name="gluLookAt.3G-c_spec"/><h2>C Specification</h2><table class="funcprototype" border="0" cellpadding="0" cellspacing="0"><tr><td valign="top"><code>void<tt>gluLookAt</tt></code></td><td valign="top"><code>(</code></td><td valign="top"><code>GLdouble<i><tt>eyeX</tt></i>, GLdouble<i><tt>eyeY</tt></i>, GLdouble<i><tt>eyeZ</tt></i>, GLdouble<i><tt>centerX</tt></i>, GLdouble<i><tt>centerY</tt></i>, GLdouble<i><tt>centerZ</tt></i>, GLdouble<i><tt>upX</tt></i>, GLdouble<i><tt>upY</tt></i>, GLdouble<i><tt>upZ</tt></i>);</code></td></tr></table></div><div class="refsynopsisdiv"><a name="gluLookAt.3G-python_spec"/><h2>Python Specification</h2><table class="funcprototype" border="0" cellpadding="0" cellspacing="0"><tr><td valign="top"><code><tt>gluLookAt</tt></code></td><td valign="top"><code>(</code></td><td valign="top"><code><i><tt>eyeX</tt></i>, <i><tt>eyeY</tt></i>, <i><tt>eyeZ</tt></i>, <i><tt>centerX</tt></i>, <i><tt>centerY</tt></i>, <i><tt>centerZ</tt></i>, <i><tt>upX</tt></i>, <i><tt>upY</tt></i>, <i><tt>upZ</tt></i>) →<tt>None</tt></code></td></tr></table></div><div class="refsect1" lang="en"><a name="gluLookAt.3G-parameters"/><h2>Parameters</h2><div class="variablelist"><dl><dt><span class="term"><i><tt>eyeX</tt></i>, <i><tt>eyeY</tt></i>, <i><tt>eyeZ</tt></i></span></dt><dd>
Specifies the position of the eye point.
</dd><dt><span class="term"><i><tt>centerX</tt></i>, <i><tt>centerY</tt></i>, <i><tt>centerZ</tt></i></span></dt><dd>
Specifies the position of the reference point.
</dd><dt><span class="term"><i><tt>upX</tt></i>, <i><tt>upY</tt></i>, <i><tt>upZ</tt></i></span></dt><dd>
Specifies the direction of the <i><tt>up</tt></i> vector.
</dd></dl></div></div><div class="refsect1" lang="en"><a name="gluLookAt.3G-description"/><h2>Description</h2><p>
<tt>gluLookAt</tt> creates a viewing matrix derived from an eye point, a reference point indicating the
center of the scene, and an <i><tt>UP</tt></i> vector.
</p><p>
The matrix maps the reference point to the negative <i><tt>z</tt></i> axis and the eye point to the origin. When
a typical projection matrix is used, the center of the scene therefore maps to the center of the viewport. Similarly,
the direction described by the <i><tt>UP</tt></i> vector projected onto the viewing plane is mapped to the
positive <i><tt>y</tt></i> axis so that it points upward in the viewport. The <i><tt>UP</tt></i> vector
must not be parallel to the line of sight from the eye point to the reference point.
</p><p>
Let </p><div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" mode="display" overflow="scroll">
<mml:mrow>
<mml:mi>F</mml:mi>
<mml:mo>=</mml:mo>
<mml:mrow>
<mml:mo>(</mml:mo>
<mml:mrow>
<mml:mtable>
<mml:mtr>
<mml:mtd columnalign="center">
<mml:mi>centerX</mml:mi>
</mml:mtd>
<mml:mtd columnalign="center">
<mml:mo>-</mml:mo>
</mml:mtd>
<mml:mtd columnalign="center">
<mml:mi>eyeX</mml:mi>
</mml:mtd>
</mml:mtr>
<mml:mtr>
<mml:mtd columnalign="center">
<mml:mi>centerY</mml:mi>
</mml:mtd>
<mml:mtd columnalign="center">
<mml:mo>-</mml:mo>
</mml:mtd>
<mml:mtd columnalign="center">
<mml:mi>eyeY</mml:mi>
</mml:mtd>
</mml:mtr>
<mml:mtr>
<mml:mtd columnalign="center">
<mml:mi>centerZ</mml:mi>
</mml:mtd>
<mml:mtd columnalign="center">
<mml:mo>-</mml:mo>
</mml:mtd>
<mml:mtd columnalign="center">
<mml:mi>eyeZ</mml:mi>
</mml:mtd>
</mml:mtr>
</mml:mtable>
</mml:mrow>
<mml:mo>)</mml:mo>
</mml:mrow>
</mml:mrow>
</mml:math></div><p>
</p><p>
Let <i><tt>UP</tt></i> be the vector <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
<mml:mrow>
<mml:mo>(</mml:mo>
<mml:mi>upX</mml:mi>
<mml:mi>upY</mml:mi>
<mml:mi>upZ</mml:mi>
<mml:mo>)</mml:mo>
</mml:mrow>
</mml:math>.
</p><p>
Then normalize as follows: </p><div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" mode="display" overflow="scroll">
<mml:mrow>
<mml:mi>f</mml:mi>
<mml:mo>=</mml:mo>
<mml:mfrac>
<mml:mi>F</mml:mi>
<mml:mrow>
<mml:mo>|</mml:mo>
<mml:mo>|</mml:mo>
<mml:mi>F</mml:mi>
<mml:mo>|</mml:mo>
<mml:mo>|</mml:mo>
</mml:mrow>
</mml:mfrac>
</mml:mrow>
</mml:math></div><p>
</p><p>
</p><div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" mode="display" overflow="scroll">
<mml:mrow>
<mml:msup>
<mml:mi>UP</mml:mi>
<mml:mo>'</mml:mo>
</mml:msup>
<mml:mo>=</mml:mo>
<mml:mfrac>
<mml:mi>UP</mml:mi>
<mml:mrow>
<mml:mo>|</mml:mo>
<mml:mo>|</mml:mo>
<mml:mi>UP</mml:mi>
<mml:mo>|</mml:mo>
<mml:mo>|</mml:mo>
</mml:mrow>
</mml:mfrac>
</mml:mrow>
</mml:math></div><p>
</p><p>
Finally, let <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
<mml:mrow>
<mml:mi>s</mml:mi>
<mml:mo>=</mml:mo>
<mml:mi>f</mml:mi>
<mml:mo></mml:mo>
<mml:msup>
<mml:mi>UP</mml:mi>
<mml:mo>'</mml:mo>
</mml:msup>
</mml:mrow>
</mml:math>, and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
<mml:mrow>
<mml:mi>u</mml:mi>
<mml:mo>=</mml:mo>
<mml:mi>s</mml:mi>
<mml:mo></mml:mo>
<mml:mi>f</mml:mi>
</mml:mrow>
</mml:math>.
</p><p>
M is then constructed as follows: </p><div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" mode="display" overflow="scroll">
<mml:mrow>
<mml:mi>M</mml:mi>
<mml:mo>=</mml:mo>
<mml:mrow>
<mml:mo>(</mml:mo>
<mml:mtable>
<mml:mtr>
<mml:mtd columnalign="center">
<mml:mi>s</mml:mi>
<mml:mo>[</mml:mo>
<mml:mn>0</mml:mn>
<mml:mo>]</mml:mo>
</mml:mtd>
<mml:mtd columnalign="center">
<mml:mi>s</mml:mi>
<mml:mo>[</mml:mo>
<mml:mn>1</mml:mn>
<mml:mo>]</mml:mo>
</mml:mtd>
<mml:mtd columnalign="center">
<mml:mi>s</mml:mi>
<mml:mo>[</mml:mo>
<mml:mn>2</mml:mn>
<mml:mo>]</mml:mo>
</mml:mtd>
<mml:mtd columnalign="center">
<mml:mn>0</mml:mn>
</mml:mtd>
</mml:mtr>
<mml:mtr>
<mml:mtd columnalign="center">
<mml:mi>u</mml:mi>
<mml:mo>[</mml:mo>
<mml:mn>0</mml:mn>
<mml:mo>]</mml:mo>
</mml:mtd>
<mml:mtd columnalign="center">
<mml:mi>u</mml:mi>
<mml:mo>[</mml:mo>
<mml:mn>1</mml:mn>
<mml:mo>]</mml:mo>
</mml:mtd>
<mml:mtd columnalign="center">
<mml:mi>u</mml:mi>
<mml:mo>[</mml:mo>
<mml:mn>2</mml:mn>
<mml:mo>]</mml:mo>
</mml:mtd>
<mml:mtd columnalign="center">
<mml:mn>0</mml:mn>
</mml:mtd>
</mml:mtr>
<mml:mtr>
<mml:mtd columnalign="center">
<mml:mo>-f</mml:mo>
<mml:mo>[</mml:mo>
<mml:mn>0</mml:mn>
<mml:mo>]</mml:mo>
</mml:mtd>
<mml:mtd columnalign="center">
<mml:mo>-f</mml:mo>
<mml:mo>[</mml:mo>
<mml:mn>1</mml:mn>
<mml:mo>]</mml:mo>
</mml:mtd>
<mml:mtd columnalign="center">
<mml:mo>-f</mml:mo>
<mml:mo>[</mml:mo>
<mml:mn>2</mml:mn>
<mml:mo>]</mml:mo>
</mml:mtd>
<mml:mtd columnalign="center">
<mml:mn>0</mml:mn>
</mml:mtd>
</mml:mtr>
<mml:mtr>
<mml:mtd columnalign="center">
<mml:mn>0</mml:mn>
</mml:mtd>
<mml:mtd columnalign="center">
<mml:mn>0</mml:mn>
</mml:mtd>
<mml:mtd columnalign="center">
<mml:mn>0</mml:mn>
</mml:mtd>
<mml:mtd columnalign="center">
<mml:mn>1</mml:mn>
</mml:mtd>
</mml:mtr>
</mml:mtable>
<mml:mo>)</mml:mo>
</mml:mrow>
</mml:mrow>
</mml:math></div><p>
</p><p>
and <tt>gluLookAt</tt> is equivalent to glMultMatrixf(M); glTranslated (-eyex, -eyey, -eyez);
</p></div><div class="refsect1" lang="en"><a name="gluLookAt.3G-see_also"/><h2>See Also</h2><p>
<span class="simplelist"><a href="glFrustum.3G.xml">glFrustum</a>, <a href="gluPerspective.3G.xml">gluPerspective</a></span>
</p></div></div><div class="navfooter"><hr/><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="gluLoadSamplingMatrices.3G.xml">Prev</a></td><td width="20%" align="center"><a accesskey="u" href="reference-GLU.xml">Up</a></td><td width="40%" align="right"><a accesskey="n" href="gluNewNurbsRenderer.3G.xml">Next</a></td></tr><tr><td width="40%" align="left" valign="top">gluLoadSamplingMatrices</td><td width="20%" align="center"><a accesskey="h" href="index.xml">Home</a></td><td width="40%" align="right" valign="top">gluNewNurbsRenderer</td></tr></table></div></body></html>
|
