{"id":762,"date":"2018-11-01T18:56:26","date_gmt":"2018-11-01T18:56:26","guid":{"rendered":"https:\/\/www.katsbits.com\/codex\/?p=762"},"modified":"2023-09-07T15:54:02","modified_gmt":"2023-09-07T14:54:02","slug":"flip-normals","status":"publish","type":"post","link":"https:\/\/www.katsbits.com\/codex\/flip-normals\/","title":{"rendered":"Flip Normals (inverted faces)"},"content":{"rendered":"<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_83 counter-hierarchy ez-toc-counter ez-toc-light-blue ez-toc-container-direction\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">Table of Contents<\/p>\n<label for=\"ez-toc-cssicon-toggle-item-6a1706b6c16e2\" class=\"ez-toc-cssicon-toggle-label\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/label><input type=\"checkbox\"  id=\"ez-toc-cssicon-toggle-item-6a1706b6c16e2\"  aria-label=\"Toggle\" \/><nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/www.katsbits.com\/codex\/flip-normals\/#flip-selected-faces\" >Flip Selected Faces<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/www.katsbits.com\/codex\/flip-normals\/#recalculate-faces\" >Recalculate Faces<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/www.katsbits.com\/codex\/flip-normals\/#face-orientation\" >Face Orientation<\/a><\/li><\/ul><\/nav><\/div>\n<p>In newer versions of Blender the previously available Tool Shelf buttons <b>Flip Direction<\/b> and <b>Recalculate<\/b>, typically used to flip inverted surfaces that made meshes appear inside-out, have been moved to the main <b>Mesh<\/b> menu upper-left of the <b>3D View<\/b>. As the option is now context sensitive it only appears as a menu option in <b>Edit Mode<\/b>.<\/p>\n<blockquote><p><b>Design note<\/b>: the <b>Mesh<\/b> menu is specific to <b>Edit Mode<\/b> and does not appear unless that particular editing context is active.<\/p><\/blockquote>\n<h3><span class=\"ez-toc-section\" id=\"flip-selected-faces\"><\/span>Flip Selected Faces<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>To access the option and\/or correct an inside-out or inverted face, first select the errant mesh element in <strong>Edit Mode<\/strong> [1] (using vertex, edge or face) and from the <b>Mesh<\/b> menu upper-left click <b>Normals<\/b> [2] then <b>Flip<\/b> [3] from the options that appear &#8211; <b>Mesh \u00bb Normals \u00bb Flip<\/b>. Alternatively use <span class=\"shortcutkey\">Alt<\/span> + <span class=\"shortcutkey\">N<\/span> to access the <b>Normals<\/b> context menu then select <b>Flip<\/b>. The highlighted inverted face\/s will immediately invert based on their current orientation.<\/p>\n<blockquote><p><b>Design note<\/b>: when selecting errant faces using vertices or edges make sure all component elements are included to the degree that the inverted faces highlight.<\/p><\/blockquote>\n<p><a href=\"https:\/\/www.katsbits.com\/images\/tutorials\/normals\/flip-normals.jpg\" target=\"_blank\" rel=\"noopener\"><img decoding=\"async\" style=\"width: 100%; height: auto;\" src=\"https:\/\/www.katsbits.com\/images\/tutorials\/normals\/flip-normals.jpg\" alt=\"Meshes or faces that appear inside out or inverted are fixed from the 3D Views 'Mesh' menu\" width=\"900px\" height=\"500px\" border=\"0\" \/><\/a><br \/>\n<i>The option to flip or invert faces [1] is an <strong>Edit Mode<\/strong> option only (accessible only when editing meshes), click <b>Mesh \u00bb Normals \u00bb Flip<\/b> [2 &amp; 3] with an individual face or group selected.<\/i><br \/>\n<!-- <video poster=\"\" controls=\"controls\" width=\"100%\" height=\"auto\">\n<source src=\"\/images\/tutorials\/viewpoint-navigation.mp4\" type=\"video\/mp4\" \/>\n<source src=\"https:\/\/www.katsbits.com\/images\/tutorials\/normals\/flip-normals.ogg\" type=\"video\/ogg\" \/>\n<source src=\"https:\/\/www.katsbits.com\/images\/tutorials\/normals\/flip-normals.webm\" type=\"video\/webm\" \/><\/video>\n<i>To fix inverted faces, or meshes that appear inside-out, in <b>Edit Mode<\/b> use the <b>Flip Normals<\/b> feature available in the <b>Normals<\/b> submenu - <b>Mesh \u00bb Normals \u00bb Flip Normals<\/b>.<\/i> --><\/p>\n<h3><span class=\"ez-toc-section\" id=\"recalculate-faces\"><\/span>Recalculate Faces<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>As an alternative to selectively inverting faces, or re-orientating a large mixed selection so everything points in one direction,\u00a0 inwards or outwards, use <b>Recalculate Outside<\/b> (<i><span class=\"shortcutkey\">Shift<\/span> + <span class=\"shortcutkey\">N<\/span><\/i>) or <b>Recalculate Inside<\/b> (<i><span class=\"shortcutkey\">Shift<\/span> + <span class=\"shortcutkey\">Ctrl<\/span> + <span class=\"shortcutkey\">N<\/span><\/i>) options. To do this and force the orientation in one direction or the other, in <b>Edit Mode<\/b> <a href=\"https:\/\/www.katsbits.com\/codex\/select\/\">select the entire mesh<\/a> (<span class=\"shortcutkey\">A<\/span>) and access the <b>Mesh<\/b> menu. Here select <b>Normals \u00bb Recalculate Outside<\/b> to flip faces\/selections outwards, or <b>Normals \u00bb Recalculate Inside<\/b> to invert selections inwards &#8211; <b><i>Mesh \u00bb Normals \u00bb Recalculate Outside\/Inside<\/i><\/b>.<\/p>\n<blockquote><p><b>Design note<\/b>: in previous versions of Blender Recalculate tended to orientate faces randomly depending on the predominance of inwards or outwards facing surfaces prior to use. For Blender 2.8+ this is no longer the case, Recalculate Inwards and Recalculate Outwards forceably re-orientate selections based on the option selected, either in or out but not both.<\/p><\/blockquote>\n<p><a href=\"https:\/\/www.katsbits.com\/images\/tutorials\/normals\/recalculate-normals.jpg\" target=\"_blank\" rel=\"noopener\"><img decoding=\"async\" style=\"width: 100%; height: auto;\" src=\"https:\/\/www.katsbits.com\/images\/tutorials\/normals\/recalculate-normals.jpg\" alt=\"IF faces are randomly inverted use Recalculate to flip everything in one direction\" width=\"900px\" height=\"500px\" border=\"0\" \/><\/a><br \/>\n<i>For instances where surfaces are randomly facing one way or the other [4], or there are too many to select and manually process, use Recalculate Inwards\/Outwards [5] to force everything to face the same direction, in or out, regardless &#8211; make a selection (individual, group or all) then click the <b>Mesh<\/b> menu, <b>Normals<\/b> then <b>Recalculate Inwards<\/b>\/<b>Outwards<\/b>.<\/i><br \/>\n<!-- <video poster=\"\" controls=\"controls\" width=\"100%\" height=\"auto\">\n<source src=\"\/images\/tutorials\/viewpoint-navigation.mp4\" type=\"video\/mp4\" \/>\n<source src=\"https:\/\/www.katsbits.com\/images\/tutorials\/normals\/recalculate-outside.ogg\" type=\"video\/ogg\" \/>\n<source src=\"https:\/\/www.katsbits.com\/images\/tutorials\/normals\/recalculate-outside.webm\" type=\"video\/webm\" \/>\n<\/video>\n<i>When a mesh contains many inverted faces their orientation can be forced to face inwards or outwards using the <b>Recalculate Inside<\/b> and <b>Recalculate Outside<\/b> options also available under the <b>Normals<\/b> submenu - select all the errant faces (or everything) and click <b>Mesh \u00bb Normals \u00bb Recalculate Inside<\/b>\/<b>Outside<\/b>.<\/i> --><\/p>\n<h3><span class=\"ez-toc-section\" id=\"face-orientation\"><\/span>Face Orientation<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>To assist determining which way a face might be pointing, especially if <a href=\"https:\/\/www.katsbits.com\/codex\/backface-culling\/\"><i>Backface Culling<\/i><\/a> is not disabled in <i>Viewport Overlays<\/i> or <i>Viewport Shading<\/i> options (depending on the viewport display mode) or a given materials <i>Settings<\/i> properties, Blender 2.8+ includes an option to colour tint faces based on their orientation, <b>RED<\/b> for surfaces pointing <b><i>inwards<\/i><\/b> and <b>BLUE<\/b> for those pointing <b><i>outwards<\/i><\/b>, making it much easier to see at a glance what&#8217;s going on, which then allows for individual faces to be flipped or recalculated as needed. To use, click the <b>Overlays<\/b> button upper-right of the 3D View [6] and from the menu select <b>Face Orientation<\/b> [7] &#8211; <b>Overlays \u00bb Face Orientation<\/b>. Everything will immediately tint blue\/red based on their orientation. To disable, repeat, select <i>Overlays \u00bb Face Orientation<\/i>.<\/p>\n<blockquote><p><b>Design note<\/b>: if <b>X-Ray<\/b> (<span class=\"shortcutkey\">Alt<\/span> + <span class=\"shortcutkey\">Z<\/span>) is active for any of the Viewport Shading modes, Wireframe, Solid etc., Face Orientation won&#8217;t work.<\/p><\/blockquote>\n<p><a href=\"https:\/\/www.katsbits.com\/images\/tutorials\/normals\/backface-culling-off.jpg\" target=\"_blank\" rel=\"noopener\"><img decoding=\"async\" style=\"width: 100%; height: auto;\" src=\"https:\/\/www.katsbits.com\/images\/tutorials\/normals\/backface-culling-off.jpg\" alt=\"Backface Culling is off\" width=\"900px\" height=\"500px\" border=\"0\" \/><\/a><br \/>\n<a href=\"https:\/\/www.katsbits.com\/images\/tutorials\/normals\/face-orientation.jpg\" target=\"_blank\" rel=\"noopener\"><img decoding=\"async\" style=\"width: 100%; height: auto;\" src=\"https:\/\/www.katsbits.com\/images\/tutorials\/normals\/face-orientation.jpg\" alt=\"Face Orientation used to determined which way faces point\" width=\"900px\" height=\"500px\" border=\"0\" \/><\/a><br \/>\n<i>If <b>Backface Culling<\/b> is disabled (off) it can be difficult to determine which way a given surfaces is pointing because both front and back of the mesh are the same. In this situation using the <b>Overlays<\/b> [6] setting <b>Face Orientation<\/b> [7] can help as it tints surfaces based on their orientation, inwards or outwards.<\/i><\/p>\n","protected":false},"excerpt":{"rendered":"","protected":false},"author":1,"featured_media":795,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[34,230],"tags":[558,383,720,380,379,378,174,391,390,392],"class_list":["post-762","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-blender","category-tutorials","tag-backface-culling","tag-face-normals","tag-face-orientation","tag-flip-normal","tag-flipped-normals","tag-inverted-faces","tag-normals","tag-recalculate-inside","tag-recalculate-normals","tag-recalculate-outside"],"post_mailing_queue_ids":[],"_links":{"self":[{"href":"https:\/\/www.katsbits.com\/codex\/wp-json\/wp\/v2\/posts\/762","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.katsbits.com\/codex\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.katsbits.com\/codex\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.katsbits.com\/codex\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.katsbits.com\/codex\/wp-json\/wp\/v2\/comments?post=762"}],"version-history":[{"count":6,"href":"https:\/\/www.katsbits.com\/codex\/wp-json\/wp\/v2\/posts\/762\/revisions"}],"predecessor-version":[{"id":5197,"href":"https:\/\/www.katsbits.com\/codex\/wp-json\/wp\/v2\/posts\/762\/revisions\/5197"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.katsbits.com\/codex\/wp-json\/wp\/v2\/media\/795"}],"wp:attachment":[{"href":"https:\/\/www.katsbits.com\/codex\/wp-json\/wp\/v2\/media?parent=762"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.katsbits.com\/codex\/wp-json\/wp\/v2\/categories?post=762"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.katsbits.com\/codex\/wp-json\/wp\/v2\/tags?post=762"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}