{"id":825,"date":"2025-12-30T05:40:03","date_gmt":"2025-12-29T20:40:03","guid":{"rendered":"https:\/\/ryohirano.com\/?p=825"},"modified":"2026-01-03T13:04:14","modified_gmt":"2026-01-03T04:04:14","slug":"diary20251230","status":"publish","type":"post","link":"https:\/\/ryohirano.com\/en\/diary20251230\/","title":{"rendered":"Blender: Learning Geometry Nodes\ud83d\udee0\ufe0f"},"content":{"rendered":"

My upcoming animated film, “Night in the Eyewall<\/strong>“, is set on a stormy night during a typhoon.<\/p>\n

Because of this, I need trees and forest leaves that sway realistically in the wind for the background. I figured if I could create them in Blender*<\/strong>, it would make the workflow much smoother…<\/p>\n

To build a forest, if I were to model every single tree one by one… I\u2019d never finish in a lifetime.
\nI thought about making a few patterns and copy-pasting them, but I was worried it might look a bit cheap.
\nSo, I decided to use “Geometry Nodes”*<\/strong> to create a “Procedural Tree”\u2014a versatile tool where I can adjust the trunk shape and the amount of branches and leaves just by tweaking parameters.<\/p>\n

Geometry Nodes are built by connecting various “Logic Nodes” with lines. It feels a bit like programming, and since I had never touched it before, I was completely lost.
\nI asked Google\u2019s AI, Gemini, to be my tutor, and we progressed step-by-step, question by question.
\nGemini 3 is incredibly capable with almost no misinformation, and it actually worked! Moreover, it explained the function of each node in detail as we went along, so I think I\u2019ve grasped at least the absolute basics of Geometry Nodes.<\/p>\n

\"\"<\/p>\n

I can adjust the height, the curvature, the number of branches, and more.
\nWith this, I can place various iterations of trees on the screen, so it shouldn’t look unnatural. Now, I need to make a coniferous version too.<\/p>\n

While I was at it, I also tried using Geometry Nodes to recreate the grass in the forest swaying in the wind.
\nPhysics simulations can be very heavy on the PC, so I want to avoid them as much as possible.<\/p>\n

\"\"<\/p>\n

The grass and leaves are simply drawn with a brush. It gives them an analog vibe, which is quite cute.
\nThe length, color, and other attributes are adjusted to vary randomly.<\/p>\n

\"\"<\/p>\n

With Geometry Nodes alone, the planes just ended up wobbling back and forth.
\nSo, I also used the Wave Modifier on the base assets to create a rippling effect.<\/p>\n

I hope it looks like a somewhat strong wind is blowing.<\/p>\n

\"\"
\nThe full view of the “Procedural Tree” Geometry Nodes.
\nBlue is the trunk, yellow is the branches, red is the sub-branches growing from them, and green is the leaves.<\/p>\n

I built it by combining commands like: “give the line a surface,” “make it taller,” “taper the tips,” “make it curvy,” “set the number of branches to X,” “set the branch direction\/angle to…” and so on.<\/p>\n

*Blender<\/strong>… A world-famous **free** software that can do almost anything related to 3D.
\n*Geometry Nodes<\/strong>… A feature that allows you not just to model an object, but to create the “recipe” for the construction itself.<\/p>","protected":false},"excerpt":{"rendered":"

My upcoming animated film, “Night in the Eyewall“, is set on a stormy night during a typhoon. Because of this,…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[3,55,54,45],"class_list":["post-825","post","type-post","status-publish","format-standard","hentry","category-uncategorized","tag-animation","tag-blender","tag-nightintheeyewall","tag-workinprogress"],"_links":{"self":[{"href":"https:\/\/ryohirano.com\/en\/wp-json\/wp\/v2\/posts\/825","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ryohirano.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ryohirano.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ryohirano.com\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ryohirano.com\/en\/wp-json\/wp\/v2\/comments?post=825"}],"version-history":[{"count":7,"href":"https:\/\/ryohirano.com\/en\/wp-json\/wp\/v2\/posts\/825\/revisions"}],"predecessor-version":[{"id":971,"href":"https:\/\/ryohirano.com\/en\/wp-json\/wp\/v2\/posts\/825\/revisions\/971"}],"wp:attachment":[{"href":"https:\/\/ryohirano.com\/en\/wp-json\/wp\/v2\/media?parent=825"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ryohirano.com\/en\/wp-json\/wp\/v2\/categories?post=825"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ryohirano.com\/en\/wp-json\/wp\/v2\/tags?post=825"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}