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 …

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Video: An Introduction to 3D Graphics with Metal in Swift

In November 2014, I was privileged to deliver a talk to San Francisco’s Swift Language User Group, hosted by Realm. They’ve now uploaded the video, with subtitles and synchronized slide deck to their site. You can view the video here.

Mipmapping and the Blit Command Encoder

In this article we will learn about mipmapping, an important technique for rendering textured objects at a distance. We will find out why mipmapping is important, how it complements regular texture filtering, and how to use the blit command encoder to generate mipmaps efficiently on the GPU.

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 …

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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.

Fundamentals of Image Processing in Metal

In this post, we will start exploring the world of image processing with the Metal shading language. We will create a framework capable of representing chains of image filters, then write a pair of image filters that will allow us to adjust the saturation and blur of an image. The end result will be an …

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Introduction to Compute Programming in Metal

This post is an introduction to topics in compute (or data-parallel) programming. It is designed to be read before its companion article, Fundamentals of Image Processing. In this article, we will cover the basics of setting up the compute pipeline and executing kernel functions on large sets of data in parallel. The companion article covers …

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Textures and Samplers in Metal

Textures are a central topic in rendering. Although they have many uses, one of their primary purposes is to provide a greater level of detail to surfaces than can be achieved with vertex colors alone. In this post, we’ll talk about texture mapping, which helps us bring virtual characters to life. We’ll also introduce samplers, …

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Feature Sets and Capabilities

One of the changes made to the Metal API in the iOS 8 GM was the addition of the supportsFeatureSet: method to the MTLDevice protocol. The purpose of this method is to differentiate between devices powered by the A7 and A8 processor, because these chips offer different capabilities to Metal.

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. …

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