I expected to have to wait 12 more years to write this post. Back in 2017, Eric Lengyel published the landmark paper, “GPU-Centered Font Rendering Directly from Glyph Outlines” in the Journal of Computer Graphics Techniques. This paper introduced the Slug algorithm, a way of efficiently rasterizing text on the GPU without first rasterizing to […]
Category: Rendering
Introduction to Tessellation in Metal
In this article we will take a look at how to do tessellation on the GPU with Metal. Tessellation is a powerful technique for generating geometry dynamically with many use cases from CAD/CAM to game development and beyond. This article discusses the fundamentals of tessellation and how to do it in Metal; future articles will […]
Vertex Data and Vertex Descriptors
The purpose of this article is to describe and explore a foundational concept in Metal: vertex descriptors. Vertex descriptors are the glue between your application code (written in Objective-C or Swift) and your shader functions (written in the Metal Shading Language). They describe the shape of data consumed by your shaders. When I was writing […]
Rendering 3D Text with Core Text and libtess2
In this article, we’ll discuss how to create and render 3D text with Metal. Most applications need to render text, and there are many techniques for drawing 2D text with graphics APIs, from pre-rasterized font atlases, to signed-distance field methods like Chris Green’s seminal work at Valve or GLyphy, to cutting-edge vector-based solutions like Slug. […]
Writing a Modern Metal App from Scratch: Part 2
In the previous article, we wrote enough Metal code to get the spinning silhouette of a teapot on the screen, but that still leaves a lot to be desired as far as a “modern” app is concerned. In this article, we’ll further flesh out the app and introduce lighting, materials, texturing, and managing multiple objects […]
Translucency and Transparency in Metal
Introduction One of the topics we’ve handily avoided so far in our exploration of Metal is rendering of materials that are not opaque. In this post, we’ll explore a couple of related techniques for achieving transparency and translucency: alpha testing and alpha blending. The sample scene for this post is a desert containing many palm […]
Instanced Rendering in Metal
In this article, we will discuss an important technique for efficiently drawing many objects with a single draw call: instanced rendering. This technique helps you get the most out of the GPU while keeping memory and CPU usage to a minimum. The sample app for this post renders several dozen animated cows moving on top […]
Cubic Environment Mapping in Metal: Reflection and Refraction
In this post, we’ll talk about some of the more advanced features of texturing in Metal. We’ll apply a cube map to a skybox to simulate a detailed environment surrounding the scene. We’ll also introduce a technique called cubic environment mapping to simulate reflection and refraction, to further enhance the realism of our virtual world.
Up and Running with Metal, Part 3: Lighting and Rendering in 3D
In this post, we’ll finally start rendering in 3D. In order to get there, we’ll talk about how to load 3D model data from disk, how to tell Metal to draw from a vertex buffer using indices, and how to manipulate objects in real time. This post assumes that you know a little linear algebra. […]
Up and Running with Metal, Part 2: Drawing Triangles
In our inaugural post of the series, we got a glimpse of many of the essential moving parts of the Metal framework: devices, textures, command buffers, and command queues. Although that post was long, it couldn’t possibly cover all these things in detail. This post will add a little more depth to the discussion of […]