Author: Linden Reid

Game developer and tutorial writer :D

Procedural Greeble Tutorial

DISCLAIMER #1: Code presented here is pseudocode that does NOT necessarily reflect production Limit Theory code.

DISCLAIMER #2: This tutorial assumes you have at least basic knowledge of 3D geometry and related math.

Firstly, let me complain that ‘greeble’ is an abhorrent word and should be banished.

Ok, now that’s off my chest… 😂

Greebles are small, repeated details added to a model to give it a sense of scale and a particular aesthetic. Certain classic sci-fi films popularized them, back when “model” more often meant a physical sculpture:

star-destroyer-back

If you’re familiar with how to extrude the polys on a mesh, as described in my procedural mesh extrusion tutorial, then you already know how to add greebles to one. Not to spoil the fun, but to put it simply:

Adding simple greebles to a mesh can be accomplished by extruding all of the polys of the mesh by a random length.

However, you might have noticed that the above tutorial focuses only on extruding triangles, whereas the header image for this tutorial has square greebles. I had set up the mesh so that it was split into quads, and many of the meshes in LT (and possibly in your game) are made of polys with more than 3 indicies. So, in this tutorial, we’ll learn how to extrude a poly with n indicies, and we’ll apply that algorithm across a whole mesh to add greebles. We’ll also learn a couple of ways to vary the greebling algorithm to get less uniform results.

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Simple Mesh Tessellation & Triangulation Tutorial

DISCLAIMER #1: Code presented here is pseudocode that does NOT necessarily reflect production Limit Theory code.

DISCLAIMER #2: This tutorial assumes you have at least basic knowledge of 3D geometry and related math.

Sometimes, we want to add detail to a mesh without changing its shape. We may need to break up polygons with lots of verticies into triangles, a necessary step before handing it to the renderer; or prepare a mesh for a warp like stellation or extrusion to ensure that it’ll have lots of small details. This is where tessellation and triangulation come in handy! The algorithms I’m going to be showing in this tutorial break up the polys that make up a mesh without changing the shape of the mesh.

Continue reading Simple Mesh Tessellation & Triangulation Tutorial

Procedural Sphere / Ellipsoid Tutorial

DISCLAIMER #1: Code presented here is pseudocode that does NOT necessarily reflect production Limit Theory code.

DISCLAIMER #2: This tutorial assumes you have at least basic knowledge of 3D geometry and related math.

I’ve seen plenty of tutorials for procedural spheres online, but most of them present the pseudocode (or even worse, language-specific code) for a sphere without explaining why it works. But if you want to really learn how to create procedural meshes – especially creative ones like torii or mesh warps like stellation and extrusion – it helps massively to first understand how the simple ones work.

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Procedural Torus Tutorial

DISCLAIMER #1: Code presented here is pseudocode that does NOT necessarily reflect production Limit Theory code.

DISCLAIMER #2: This tutorial assumes you have at least basic knowledge of 3D geometry and related math.

The torus is probably my favorite shape right now because of the contrast between how daunting it looks to build and how beautifully simple it actually is. I never thought I would be good at math, much less enjoy it, but here I am, a professional graphics programmer, loving and learning math-heavy algorithms. Visualizing math made all the difference. The torus is a stunning example of how beautiful math can actually be,  once you get away from dry, academic, rote math and into the applied realms of proceduralism, graphics, and games.

I want to take the time to explain why these algorithms work on a conceptual level. If you understand why they work, it’s an easy leap from the simple torus on the left of the header image to the fancy torus on the right.

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Procedural Mesh Extrusion Tutorial

DISCLAIMER #1: Code presented here is pseudocode that does NOT necessarily reflect production Limit Theory code.

DISCLAIMER #2: This tutorial assumes you have at least basic knowledge of 3D geometry and related math.

This week, I’m writing as many procedural generation tutorials as I can to help out participants of #PROCJAM! Today, I’m going to explain how to extrude the triangles in a mesh. For the purpose of this tutorial, extrusion is the process of copying all of the verticies in a triangle and translating them in the direction of the surface normal, so that you end up with a triangular prism.

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Procedural Stellation Tutorial

DISCLAIMER: Code presented here is pseudocode that does NOT necessarily reflect production Limit Theory code.

A quick intro to me: I’m a programmer at Procedural Reality, an indie game studio creating an infinite, procedural space exploration game called Limit Theory. You can follow @LimitTheory on Twitter if you want to see where these cool screenshots come from. In addition, all of the code presented here (in non-pseudocode form, lol) will be available and moddable once Limit Theory is released. So if you like this tutorial, be sure to keep in touch. ;0

EVERYTHING in Limit Theory is procedurally generated- including all geometry, down to every vertex and triangle. My job is to create procedural space ships and space stations. I’ve been building up a library of basic shapes to be the building blocks of these ships and a library of warps to make these shapes ~interesting~.

Note: This tutorial assumes you have at least basic knowledge of 3D geometry and related math.

Today, I want to share with y’all an algorithm for stellation. For the purpose of this tutorial, stellation is the process of extruding a triangle to converge at a point, to create a tetrahedron- a pyramid made of 4 traingular faces. The word comes from similar roots to the word “star”, as when you apply it to a polyhedron, you end up with a star shape.

Continue reading Procedural Stellation Tutorial