{"id":998,"date":"2011-11-29T08:30:25","date_gmt":"2011-11-29T08:30:25","guid":{"rendered":"https:\/\/www.cg-blog.com\/?p=998"},"modified":"2013-04-15T09:31:29","modified_gmt":"2013-04-15T09:31:29","slug":"vray-glass-fog-bias","status":"publish","type":"post","link":"https:\/\/www.cg-blog.com\/index.php\/2011\/11\/29\/vray-glass-fog-bias.htm","title":{"rendered":"Playing with V-Ray glass"},"content":{"rendered":"<p style=\"text-align: center;\">&#8211; Click <strong>LIKE<\/strong>\u00c2\u00a0above, if you like this post \ud83d\ude09 &#8211;<\/p>\n<p>Recently I posted on my <a href=\"http:\/\/www.facebook.com\/pages\/Cg-Blog\/162957861740?ref=ts\" target=\"_blank\">Facebook Page<\/a> this image I got playing with the <strong>material editor<\/strong>:<\/p>\n<p><img decoding=\"async\" loading=\"lazy\" class=\"alignnone size-full wp-image-999\" title=\"fogbias1\" src=\"https:\/\/www.cg-blog.com\/wp-content\/uploads\/2011\/11\/fogbias1.jpg\" alt=\"\" width=\"570\" height=\"428\" srcset=\"https:\/\/www.cg-blog.com\/wp-content\/uploads\/2011\/11\/fogbias1.jpg 570w, https:\/\/www.cg-blog.com\/wp-content\/uploads\/2011\/11\/fogbias1-300x225.jpg 300w\" sizes=\"(max-width: 570px) 100vw, 570px\" \/><\/p>\n<p>Guys, because you want to know more about it.. here a couple of tips \ud83d\ude09<br \/>\nThe scene is just a\u00c2\u00a0<strong>Torus Knot object\u00c2\u00a0<\/strong>with V-Ray Sun + Sky. Nothing more.<\/p>\n<p style=\"text-align: center;\"><a href=\"https:\/\/www.cg-blog.com\/index.php\/2011\/11\/29\/vray-glass-fog-bias.htm#premium\"><img decoding=\"async\" loading=\"lazy\" title=\"premium-contents-here\" src=\"https:\/\/www.cg-blog.com\/images\/more-contents-here.png\" alt=\"\" width=\"150\" height=\"131\" \/><\/a><\/p>\n<p>Here a screenshot to show you how I set this material:<\/p>\n<p><img decoding=\"async\" loading=\"lazy\" class=\"alignnone size-full wp-image-1000\" title=\"fog-bias-mated2\" src=\"https:\/\/www.cg-blog.com\/wp-content\/uploads\/2011\/11\/fog-bias-mated2.jpg\" alt=\"\" width=\"570\" height=\"428\" srcset=\"https:\/\/www.cg-blog.com\/wp-content\/uploads\/2011\/11\/fog-bias-mated2.jpg 570w, https:\/\/www.cg-blog.com\/wp-content\/uploads\/2011\/11\/fog-bias-mated2-300x225.jpg 300w\" sizes=\"(max-width: 570px) 100vw, 570px\" \/><\/p>\n<p>I used the classic V-Ray glass simulation, adding a touch of \u00c2\u00a0&#8220;<strong>negative fog bias<\/strong>&#8221; .<\/p>\n<p style=\"text-align: center;\"><em>\u00c2\u00ab Ohh Ciro, wow&#8230; it&#8217;s amazing! But&#8230;what does it mean &#8220;Negative fog bias&#8221; ?! \u00c2\u00bb :-[<\/em><\/p>\n<p>Well, a little introduction about general <strong>Fog Color settings<\/strong>\u00c2\u00a0is needed. Fog color is used to simulate colorful refractions, the default value is white (glass = neutral). But if we give a color, the glass will result in color: its color will be in relation to the thickness of the object:<\/p>\n<ul>\n<li><strong>Thin<\/strong> objects will have light and soft colors<\/li>\n<li><strong>Thick<\/strong> objects will have intense and dark colors<\/li>\n<\/ul>\n<p>Just like the real world.<\/p>\n<p>Here is the effect just for &#8220;Fog Color&#8221; option:<\/p>\n<p><img decoding=\"async\" loading=\"lazy\" class=\"alignnone size-full wp-image-1001\" title=\"fogbiasNO\" src=\"https:\/\/www.cg-blog.com\/wp-content\/uploads\/2011\/11\/fogbiasNO.jpg\" alt=\"\" width=\"570\" height=\"428\" srcset=\"https:\/\/www.cg-blog.com\/wp-content\/uploads\/2011\/11\/fogbiasNO.jpg 570w, https:\/\/www.cg-blog.com\/wp-content\/uploads\/2011\/11\/fogbiasNO-300x225.jpg 300w\" sizes=\"(max-width: 570px) 100vw, 570px\" \/><\/p>\n<p>As you can see, the color intensity changes\u00c2\u00a0for <strong>thick<\/strong> and\u00c2\u00a0<strong>thin<\/strong> areas.<\/p>\n<p><strong>Fog Bias!<\/strong>\u00c2\u00a0This parameter allows you to adjust the contrast for transition thin-thik areas. If you use negative values you can emphasize the effect producing:<\/p>\n<ul>\n<li><strong>darker<\/strong> colors for <strong>THICK<\/strong> areas<\/li>\n<li><strong>clearer <\/strong>colors\u00c2\u00a0for <strong>THIN<\/strong> areas<\/li>\n<\/ul>\n<p>For this reason negative fog bias must be accompanied by a drammatic reduction of the &#8220;Fog multiplier&#8221; (0.001) to avoid too dark areas.<\/p>\n<p>Here the parameters I used in the first image:<\/p>\n<p><strong>Fog color<\/strong>: 236 &#8211; 135 &#8211; 5 (rgb) \/ red color<br \/>\n<strong>Fog multiplier<\/strong>: 0,001 \/ brightens the refraction<br \/>\n<strong>Fog Bias<\/strong>: -1.8 \/ increase contrast thick-thin<\/p>\n<p>Result:<\/p>\n<p><img decoding=\"async\" loading=\"lazy\" class=\"alignnone size-full wp-image-1002\" title=\"sample-fog-bias-vray\" src=\"https:\/\/www.cg-blog.com\/wp-content\/uploads\/2011\/11\/sample-fog-bias-vray.jpg\" alt=\"\" width=\"570\" height=\"144\" srcset=\"https:\/\/www.cg-blog.com\/wp-content\/uploads\/2011\/11\/sample-fog-bias-vray.jpg 570w, https:\/\/www.cg-blog.com\/wp-content\/uploads\/2011\/11\/sample-fog-bias-vray-300x75.jpg 300w\" sizes=\"(max-width: 570px) 100vw, 570px\" \/><\/p>\n<p>Choose a color and balance <strong>Multipier Fog<\/strong> \/\u00c2\u00a0<strong>Fog Bias<\/strong>. The reddish color is perfect for &#8220;warm glass&#8221; , but also with other colors, fun things happen:<\/p>\n<p><img decoding=\"async\" loading=\"lazy\" class=\"alignnone size-full wp-image-1003\" title=\"fog-vergiallo\" src=\"https:\/\/www.cg-blog.com\/wp-content\/uploads\/2011\/11\/fog-vergiallo.jpg\" alt=\"\" width=\"570\" height=\"428\" srcset=\"https:\/\/www.cg-blog.com\/wp-content\/uploads\/2011\/11\/fog-vergiallo.jpg 570w, https:\/\/www.cg-blog.com\/wp-content\/uploads\/2011\/11\/fog-vergiallo-300x225.jpg 300w\" sizes=\"(max-width: 570px) 100vw, 570px\" \/><br \/>\n<a name=\"premium\"><\/a>( Fog Color = 210 &#8211; 238 &#8211; 54 \/ RGB)<\/p>\n<p>It&#8217;s just a game, but useful to learn more.<br \/>\nEnjoy it \ud83d\ude09<\/p>\n<p>(*) THANK YOU <a href=\"http:\/\/www.pixelab.be\/blog\/2008\/09\/14\/fog-bias-parameter-test-in-vray-material\/\" target=\"_blank\">Pixelab.be for inspiring me<\/a>.<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/www.cg-blog.com\/images\/more-contents-premium.jpg\" alt=\"\" \/><\/p>\n<p>[private Premium|Premium1|Premium-1year]<\/p>\n<p><strong>VIDEO<\/strong> :<\/p>\n<p><iframe loading=\"lazy\" src=\"http:\/\/player.vimeo.com\/video\/34559975?color=ff9933\" frameborder=\"0\" width=\"599\" height=\"337\"><\/iframe><\/p>\n<p><strong>What did we learn in this video?<br \/>\nVIDEO SUMMARY<\/strong>:<\/p>\n<ol>\n<li>Create the object and add V-Ray Sun \/ Sky<\/li>\n<li>Enable Global illumination for &#8220;tests&#8221;<\/li>\n<li>Create a standard Glass material<\/li>\n<li>Add fog color<\/li>\n<li>Play with Fog Multiplier and Fog bias<\/li>\n<li>Add Dof effect simply flagging &#8220;dof&#8221;<\/li>\n<\/ol>\n<p><strong>EXERCISE\u00c2\u00a0<\/strong>:<br \/>\n<a href=\"https:\/\/www.cg-blog.com\/files\/Premium\/fog-bias.zip\"> Download the file<\/a> and reproduce the image of this post.<br \/>\nFor any doubts open the &#8220;FINAL&#8221; file and check the options.<\/p>\n<p>Enjoy it!<\/p>\n<p>[\/private]<\/p>\n","protected":false},"excerpt":{"rendered":"<p>In this post you can learn how to use Fog color options to simulate warm glass and more. It&#8217;s a really easy way, you just to know a couple of simple things.<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"om_disable_all_campaigns":false},"categories":[58],"tags":[37],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.cg-blog.com\/index.php\/wp-json\/wp\/v2\/posts\/998"}],"collection":[{"href":"https:\/\/www.cg-blog.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.cg-blog.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.cg-blog.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.cg-blog.com\/index.php\/wp-json\/wp\/v2\/comments?post=998"}],"version-history":[{"count":0,"href":"https:\/\/www.cg-blog.com\/index.php\/wp-json\/wp\/v2\/posts\/998\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.cg-blog.com\/index.php\/wp-json\/wp\/v2\/media?parent=998"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.cg-blog.com\/index.php\/wp-json\/wp\/v2\/categories?post=998"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.cg-blog.com\/index.php\/wp-json\/wp\/v2\/tags?post=998"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}