{"id":15,"date":"2005-09-15T19:39:26","date_gmt":"2005-09-15T19:39:26","guid":{"rendered":"https:\/\/astrofra.com\/wordpress\/?p=15"},"modified":"2005-09-15T19:39:26","modified_gmt":"2005-09-15T19:39:26","slug":"mental-ray-ambiant-occlusion-vs-global-illum","status":"publish","type":"post","link":"https:\/\/astrofra.com\/wordpress\/index.php\/2005\/09\/15\/mental-ray-ambiant-occlusion-vs-global-illum\/","title":{"rendered":"Mental Ray | Illustration | Ambiant Occlusion VS Global Illum."},"content":{"rendered":"<p><img decoding=\"async\" src=\"\/weblog\/images\/Tuts\/house_mr_small.jpg\" alt=\"\" \/><\/p>\n<p>Lately I had the opportunity to test Mental Ray. In MR 3.4 I found <strong>&#8220;Ambiant Occlusion&#8221;<\/strong>, a shading tool that is becoming a true alternative to Global Illumination. Amb. Occ. is nothing new to CG, but it last implementation in Mental Ray comes with a lot of handy parameters :<\/p>\n<ul>\n<li><strong>sampling rate<\/strong> : quite obvious, will determine the amount of rays cast by the shader<\/li>\n<li><strong>spread angle<\/strong> : will make the probing from narrow to wide angle, thus more or less sensitive to the details around<\/li>\n<li><strong>distance<\/strong> : a critical parameter that define the probing range from near to far<\/li>\n<\/ul>\n<p>Among them, Distance is a real breakthru against Global Illumination. Small probing distance make shorter render times (more than 200% in some cases). And it gives subtles areas of shadow.<\/p>\n<p>Of course, it doesn&#8217;t take account of the <strong>&#8220;boucing energy&#8221;<\/strong> phenomenon. Fortunately that&#8217;s the funniest part of the lighting job : <strong>adding pointlights here &amp; there<\/strong> to mimic the bouncing of light. That what I did in this scene.<\/p>\n<p>In the end, hires render time came <strong>under 2 minutes<\/strong> (VS 8 minutes for a full GI solution with LW)<\/p>\n<p><img decoding=\"async\" src=\"\/weblog\/images\/Tuts\/house_mr_samples.jpg\" alt=\"\" \/><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Lately I had the opportunity to test Mental Ray. In MR 3.4 I found &#8220;Ambiant Occlusion&#8221;, a shading tool that is becoming a true alternative to Global Illumination. Amb. Occ. is nothing new to CG, but it last implementation in Mental Ray comes with a lot of handy parameters : sampling rate : quite obvious, &hellip; <a href=\"https:\/\/astrofra.com\/wordpress\/index.php\/2005\/09\/15\/mental-ray-ambiant-occlusion-vs-global-illum\/\" class=\"more-link\">Continue reading <span class=\"screen-reader-text\">Mental Ray | Illustration | Ambiant Occlusion VS Global Illum.<\/span> <span class=\"meta-nav\">&rarr;<\/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":[2,1],"tags":[],"class_list":["post-15","post","type-post","status-publish","format-standard","hentry","category-3d-techniques","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/astrofra.com\/wordpress\/index.php\/wp-json\/wp\/v2\/posts\/15"}],"collection":[{"href":"https:\/\/astrofra.com\/wordpress\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/astrofra.com\/wordpress\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/astrofra.com\/wordpress\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/astrofra.com\/wordpress\/index.php\/wp-json\/wp\/v2\/comments?post=15"}],"version-history":[{"count":0,"href":"https:\/\/astrofra.com\/wordpress\/index.php\/wp-json\/wp\/v2\/posts\/15\/revisions"}],"wp:attachment":[{"href":"https:\/\/astrofra.com\/wordpress\/index.php\/wp-json\/wp\/v2\/media?parent=15"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/astrofra.com\/wordpress\/index.php\/wp-json\/wp\/v2\/categories?post=15"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/astrofra.com\/wordpress\/index.php\/wp-json\/wp\/v2\/tags?post=15"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}