{"id":487,"date":"2007-09-12T14:17:00","date_gmt":"2007-09-12T14:17:00","guid":{"rendered":"http:\/\/www.gisdeveloper.co.kr\/?p=487"},"modified":"2017-01-29T11:08:54","modified_gmt":"2017-01-29T02:08:54","slug":"opengl-shader-19","status":"publish","type":"post","link":"http:\/\/www.gisdeveloper.co.kr\/?p=487","title":{"rendered":"OpenGL Shader &#8211; 19"},"content":{"rendered":"<p>GLSL \uc608\uc81c &#8211; Flatten Shader(\ub0a9\uc791 \uc250\uc774\ub354? =_=;)<br \/>\n\uc6d0\ubb38 : <a href=\"http:\/\/www.lighthouse3d.com\/opengl\/glsl\/index.php?flatten\">http:\/\/www.lighthouse3d.com\/opengl\/glsl\/index.php?flatten<\/a><\/p>\n<p>\uc250\uc774\ub354 \ud504\ub85c\uadf8\ub798\ubc0d\uc740 3\ucc28\uc6d0 \uc7a5\uba74\uc5d0 \uc0c8\ub85c\uc6b4 \ud6a8\uacfc\ub97c \ub123\ub294\ub370 \ub9e4\uc6b0 \uc720\uc6a9\ud558\ub2e4. \uc774 \uc791\uc740 \uc608\ub294 \ubc84\ud14d\uc2a4\uac00 \uae30\ubb18\ud55c \ubc29\ubc95\uc73c\ub85c \uac00\uacf5\ub418\ub294 \uac83\uc744 \ubcf4\uc5ec\uc900\ub2e4.<\/p>\n<p>\uba3c\uc800 3D \ubaa8\ub378\uc744 \ub0a9\uc791\ud558\uac8c \ub80c\ub354\ub9c1\uc2dc\ud0a4\uae30 \uc704\ud574, \ubaa8\ub378\ubdf0 \ubcc0\ud658\uc744 \uc801\uc6a9\ud558\uae30 \uc804\uc5d0 z \uc88c\ud45c\uc758 \uac12\uc744 0\uc73c\ub85c \uc124\uc815\ud55c\ub2e4. \uc544\ub798\uc758 \ubc84\ud14d\uc2a4 \uc250\uc774\ub354\uac00 \uc774 \uc5f0\uc0b0\uc744 \uc218\ud589\ud55c\ub2e4.<\/p>\n<pre><code class=\"html\">void main(void)\r\n{\r\n    vec4 v = vec4(gl_Vertex);\r\n    v.z = 0.0;\r\n\r\n    gl_Position = gl_ModelViewProjectionMatrix * v;\r\n}<\/code><\/pre>\n<p>\uc704\uc758 \ucf54\ub4dc\ub97c \ubcf4\uba74, \uba3c\uc800 \uc9c0\uc5ed\ubcc0\uc218(v)\uc5d0 gl_Vertex\ub97c \ubcf5\uc0ac\ud558\uace0 \uc788\ub2e4. gl_Vertex\ub294 GLSL\uc5d0\uc11c \uc81c\uacf5\ud558\ub294 Attribute \ubcc0\uc218\uc774\uba70, \ubc84\ud14d\uc2a4 \uc250\uc774\ub354\uac00 \uc218\ud589\ub418\ub294 \ub3d9\uc548\uc5d0\ub294 \uc77d\uae30\uc804\uc6a9\uc73c\ub85c \uc0ac\uc6a9\ud560 \uc218 \uc788\ub294 \ubcc0\uc218\uc774\ub2e4. \uc77d\uae30\uc804\uc6a9\uc774\uae30 \ub54c\ubb38\uc5d0 \uc9c0\uc5ed\ubcc0\uc218\uc5d0 \ubcf5\uc0ac\ud558\uc5ec \uac12\uc744 \ubcc0\ud658\uc2dc\ud0a8\uac83\uc774\ub2e4.<\/p>\n<p>\ud504\ub808\uadf8\uba3c\ud2b8 \uc250\uc774\ub354\ub294 \ub2e8\uc9c0 \uc0c9\uc0c1\ub9cc\uc744 \uc9c0\uc815\ud558\ubbc0\ub85c, \uc774\uc804 \uc139\uc158(Hello World \uc608\uc81c)\uc5d0\uc11c \uc81c\uacf5\ud55c \ucf54\ub4dc\uc640 \ub3d9\uc77c\ud558\ub2e4.<\/p>\n<p>\uc774 \uc250\uc774\ub354\ub294 \uac01 \ubc84\ud14d\uc2a4\uc758 z \uc88c\ud45c\ub97c 0\uc73c\ub85c \uc9c0\uc815\ud55c\ub2e4. \uc8fc\uc804\uc790 3D \ubaa8\ub378\uc5d0 \uc801\uc6a9\uc744 \ud574\ubcf4\uba74, \uc544\ub798\uc758 \uadf8\ub9bc\ucc98\ub7fc \ub0a9\uc791\ud574\uc9c4 \uac83\uc73c\ub85c \ud45c\ud604\ub41c\ub2e4.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter\" src=\"http:\/\/www.gisdeveloper.co.kr\/wp-content\/uploads\/1\/1398772441.jpg\" alt=\"\" width=\"510\" height=\"89\" \/>\ub410\ub2e4. \uc774\uc81c \uc5ec\uae30\uc11c \uc880 \uc751\uc6a9\uc744 \ud574\ubcf4\uc790. \ubc84\ud14d\uc2a4\uc758 z\uac12\uc744 sin\ud568\uc218\uc640 sin\ud568\uc218\uc758 \ubcc0\uc218\ub294 \ubc84\ud14d\uc2a4\uc758 x\uc88c\ud45c\ub85c \ud574\uba74 \uc8fc\uc804\uc790 \ubaa8\ub378\uc774 \ub108\uc6b8\uac70\ub9ac\ub294 \uac83\ucc98\ub7fc \ud45c\uc2dc\ub41c\ub2e4.<\/p>\n<pre><code class=\"html\">void main(void)\r\n{\r\n    vec4 v = vec4(gl_Vertex);\r\n    v.z = sin(5.0 * v.x) * 0.25;\r\n\r\n    gl_Position = gl_ModelViewProjectionMatrix * v;\r\n}<\/code><\/pre>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter\" src=\"http:\/\/www.gisdeveloper.co.kr\/wp-content\/uploads\/1\/1340554033.jpg\" alt=\"\" width=\"510\" height=\"73\" \/>\uc774\uc81c \uc774 \uac04\ub2e8\ud55c \uc608\uc81c\uc5d0 \ub9c8\uc9c0\ub9c9\uc73c\ub85c \ubc84\ud14d\uc2a4 \uc5d0\ub2c8\uba54\uc774\uc158 \ud6a8\uacfc\ub97c \uc801\uc6a9\ud574\ubcf4\uc790. \uc774 \ud6a8\uacfc\ub97c \uc704\ud574\uc11c, \uc2dc\uac04\uc744 \ucd94\uc801\ud558\uac70\ub098 \ud504\ub808\uc784 \uce74\uc6b4\ud130\ub97c \uc704\ud55c \ubcc0\uc218\uac00 \ud544\uc694\ud558\ub2e4. A vertex shader can&#8217;t keep track of values between vertices, let alone between frames. \uadf8\ub798\uc11c OpenGL \uc5b4\ud50c\ub9ac\ucf00\uc774\uc158\uc5d0 \ubcc0\uc218\ub97c \ud558\ub098 \uc815\uc758\ud558\uace0, \uc774 \ubcc0\uc218\ub97c Uniform \ubcc0\uc218\ub85c \uc250\uc774\ub354\uc5d0 \ub118\uaca8\uc57c \ud55c\ub2e4. OpenGL \uc5b4\ud50c\ub9ac\ucf00\uc774\uc158\uc5d0 &#8220;time&#8221;\uc774\ub77c\ub294 \uc774\ub984\uc758 \ubcc0\uc218\uac00 \uc788\ub294\ub370, \uc774\ubcc0\uc218\ub294 \ud504\ub808\uc784\uc744 \uce74\uc6b4\ud130\ud558\uace0, \uac19\uc740 \uc774\ub984\uc758 Uniform \ubcc0\uc218\uac00 \uc250\uc774\ub354 \uc548\uc5d0 \uc788\ub2e4.<\/p>\n<p>\ubc84\ud14d\uc2a4 \uc250\uc774\ub354\uc5d0 \ub300\ud55c \ucf54\ub4dc\ub294 \ub2e4\uc74c\uacfc \uac19\ub2e4.<\/p>\n<pre><code class=\"html\">uniform float time;\r\n\r\nvoid main(void)\r\n{\r\n    vec4 v = vec4(gl_Vertex);\r\n\r\n    v.z = sin(5.0*v.x + time*0.01)*0.25;\r\n\r\n    gl_Position = gl_ModelViewProjectionMatrix * v;\r\n}<\/code><\/pre>\n<p>Uniform \ubcc0\uc218\ub97c \uc124\uba85\ud55c \uc139\uc158\uc5d0\uc11c \uc5b8\uae09\ud588\ub4ef, OpenGL \uc5b4\ud50c\ub9ac\ucf00\uc774\uc158\uc5d0\uc11c\ub294 \ub2e4\uc74c \ub450\ub2e8\uacc4\uac00 \ud544\uc694\ud558\ub2e4.<\/p>\n<ul>\n<li>setup : Uniform \ubcc0\uc218\uc758 \uc704\uce58\ub97c \uc5bb\ub294\ub2e4.<\/li>\n<li>render : Uniform \ubcc0\uc218\ub97c \uac31\uc2e0\ud55c\ub2e4.<\/li>\n<\/ul>\n<p>setup \ubd80\ubd84\uc740 \ub2e4\uc74c \ucf54\ub4dc\uc640 \uac19\ub2e4.<\/p>\n<pre><code class=\"html\">loc = glGetUniformLocationARB(p, \"time\");<\/code><\/pre>\n<p>\uc704\uc758 \ucf54\ub4dc\uc5d0\uc11c \uc778\uc790 p\ub294 \uc250\uc774\ub354 \ud504\ub85c\uadf8\ub7a8\uc758 \ud5e8\ub4e4\uc774\uace0, time\uc740 \ubc84\ud14d\uc2a4 \uc250\uc774\ub354\uc5d0\uc11c \uc815\uc758\ud55c Uniform \ubcc0\uc218\uc758 \uc774\ub984\uc774\ub2e4. loc \ubcc0\uc218\ub294 GLint \ud615\uc774\uba70 render \ud568\uc218\uc5d0\uc11c \uc811\uadfc\ud560 \uc218 \uc788\ub294 \uc704\uce58\uc5d0 \uc815\uc758\ub418\uc5b4\uc57c \ud55c\ub2e4.<\/p>\n<p>render \ud568\uc218\ub294 \uc544\ub798\uc640 \uac19\ub2e4.<\/p>\n<pre><code class=\"html\">void renderScene(void) \r\n{\r\n    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);\r\n\r\n    glLoadIdentity();\r\n    gluLootAt(0, 0, 5, 0, 0, 0, 0, 1, 0);\r\n\r\n    glUniform1fARB(loc, time);\r\n\r\n    glutSolidTeaport(1);\r\n    time += 0.1;\r\n\r\n    glutSwapBuffers();\r\n}<\/code><\/pre>\n<p>time \ubcc0\uc218\ub294 \ucd08\uae30\ud654\ubd80\ubd84\uc5d0\uc11c \uc784\uc758\uac12\uc73c\ub85c \ucd08\uae30\ud654\ub418\uc5c8\uc744 \uac83\uc774\uace0 \ub9e4 \ud504\ub808\uc784\ub9c8\ub2e4 \uc99d\uac00\ub41c\ub2e4.<\/p>\n<p>\uc5ec\uae30\uae4c\uc9c0\uc758 \uc608\uc81c \ucf54\ub4dc\uc5d0 \ub300\ud55c \uc804\uccb4 \ucf54\ub4dc\ub294 \uc544\ub798\ub97c \ud1b5\ud574 \ub2e4\uc6b4\ub85c\ub4dc \ubc1b\uae38 \ubc14\ub780\ub2e4.<\/p>\n<p><a href=\"http:\/\/www.gisdeveloper.co.kr\/wp-content\/uploads\/1\/1167513658.zip\">1167513658.zip<\/a><a href=\"http:\/\/www.gisdeveloper.co.kr\/wp-content\/uploads\/1\/1017013023.zip\">1017013023.zip<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>GLSL \uc608\uc81c &#8211; Flatten Shader(\ub0a9\uc791 \uc250\uc774\ub354? =_=;) \uc6d0\ubb38 : http:\/\/www.lighthouse3d.com\/opengl\/glsl\/index.php?flatten \uc250\uc774\ub354 \ud504\ub85c\uadf8\ub798\ubc0d\uc740 3\ucc28\uc6d0 \uc7a5\uba74\uc5d0 \uc0c8\ub85c\uc6b4 \ud6a8\uacfc\ub97c \ub123\ub294\ub370 \ub9e4\uc6b0 \uc720\uc6a9\ud558\ub2e4. \uc774 \uc791\uc740 \uc608\ub294 \ubc84\ud14d\uc2a4\uac00 \uae30\ubb18\ud55c \ubc29\ubc95\uc73c\ub85c \uac00\uacf5\ub418\ub294 \uac83\uc744 \ubcf4\uc5ec\uc900\ub2e4. \uba3c\uc800 3D \ubaa8\ub378\uc744 \ub0a9\uc791\ud558\uac8c \ub80c\ub354\ub9c1\uc2dc\ud0a4\uae30 \uc704\ud574, \ubaa8\ub378\ubdf0 \ubcc0\ud658\uc744 \uc801\uc6a9\ud558\uae30 \uc804\uc5d0 z \uc88c\ud45c\uc758 \uac12\uc744 0\uc73c\ub85c \uc124\uc815\ud55c\ub2e4. \uc544\ub798\uc758 \ubc84\ud14d\uc2a4 \uc250\uc774\ub354\uac00 \uc774 \uc5f0\uc0b0\uc744 \uc218\ud589\ud55c\ub2e4. void main(void) { vec4 v = &hellip; <\/p>\n<p class=\"link-more\"><a href=\"http:\/\/www.gisdeveloper.co.kr\/?p=487\" class=\"more-link\">\ub354 \ubcf4\uae30<span class=\"screen-reader-text\"> &#8220;OpenGL Shader &#8211; 19&#8221;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4],"tags":[3,25],"class_list":["post-487","post","type-post","status-publish","format-standard","hentry","category-opengl","tag-opengl","tag-shader"],"_links":{"self":[{"href":"http:\/\/www.gisdeveloper.co.kr\/index.php?rest_route=\/wp\/v2\/posts\/487","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.gisdeveloper.co.kr\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.gisdeveloper.co.kr\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.gisdeveloper.co.kr\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.gisdeveloper.co.kr\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=487"}],"version-history":[{"count":1,"href":"http:\/\/www.gisdeveloper.co.kr\/index.php?rest_route=\/wp\/v2\/posts\/487\/revisions"}],"predecessor-version":[{"id":3572,"href":"http:\/\/www.gisdeveloper.co.kr\/index.php?rest_route=\/wp\/v2\/posts\/487\/revisions\/3572"}],"wp:attachment":[{"href":"http:\/\/www.gisdeveloper.co.kr\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=487"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.gisdeveloper.co.kr\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=487"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.gisdeveloper.co.kr\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=487"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}