Blog Archive

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When to NOT Linearize Your Textures

Although most images are non-linear, sometimes you should leave them that way.

Knowing how and when to deal with colour spaces in your textures files is crucial to a realistic rendering workflow.

In short: since monitors are usually non-linear devices, image files are generally stored with the inverse non-linearity baked in (the general example of which is sRGB). Since rendering calculations work in a linear space, you must convert your images back to the linear space before using them otherwise your renders will not be accurate.

While it is key that you linearize your colour textures (e.g. diffuse, specular colour, etc.), you must be very thoughtful of doing the same with your data textures (e.g. displacement, bump, etc.).

For example, lets look at a displacement:

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Inadvertent Algorithmic Cruelty

Well, that escalated quickly.

Eric Meyer, like many others, hasn't had the best of years. Facebook's "Year in Review" app inadvertently rubbed it in his face, as his most popular image was that of his recently deceased daughter. He discusses this, and the difficulty of the problem:

New post: “Inadvertent Algorithmic Cruelty”; or, when good code yields bad results, and thoughtlessly hurts people.

@meyerweb (Eric A. Meyer) on . Visit on Twitter.

The internet decided this was a Very Big Deal™, and quickly got out of control (and covered by mainstream media). Eric decided to set the record straight, and get behind the developers who created it:

New post: “Well, That Escalated Quickly”, an initial followup to my last post:

@meyerweb (Eric A. Meyer) on . Visit on Twitter.

Please read them both.

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"[If] your software doesn’t produce reproducible results, then your research results aren’t reproducible."

@mikeboers on . Visit on Twitter.

I'm slowly clueing into the terror of how the various #Minecraft server mod frameworks work...

@mikeboers on . Visit on Twitter.

Arguing for over-estimates being the best target for software development ->

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my favorite commits, by far, are the ones where I did nothing but delete code.

@codinghorror (Jeff Atwood) on . Visit on Twitter.

I miss AIR's "Instancer" shaders in @pixarsrenderman. #vfx #cg

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Repairing Python Virtual Environments

When upgrading Python breaks our environment, we can rebuild.

Python virtual environments are a fantastic method of insulating your projects from each other, allowing each project to have different versions of their requirements.

They work (at a very high level) by making a lightweight copy of the system Python, which symlinks back to the real thing whenever necessary. You can then install whatever you want in lib/pythonX.Y/site-packages (e.g. via pip), and you are good to go.

Depending on what provides your source Python, however, upgrading it can break things. For example, I use Homebrew, which (under the hood) stores everything it builds in versioned directories:

$ readlink $(which python)

Whenever there even a minor change to this Python, symlinks back to that versioned directory may not work anymore, which breaks my virtual environments:

$ python
dyld: Library not loaded: @executable_path/../.Python
  Referenced from: /Users/mikeboers/Documents/Flask-Images/venv/bin/python
  Reason: image not found
Trace/BPT trap: 5

There is an easy fix: manually remove the links back to the old Python, and rebuild the virtual environment.

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The Evils of Gamifying Git

Your green squares do you little good, and encourage bad behaviour.

Nearly two years ago, GitHub introduced contribution calendars on everyone's profile, which roughly visualize how frequently one has been "contributing" for the past year. Through 2013, mine displayed some interesting patterns and features, many of which scream that they have a story:

Having used GitHub as the primary code host for multiple full-time jobs, and a few growing open-source projects, I now believe that these calendars introduce, for me, two negative effects that vastly outweigh their benefits.

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Seems like LibreSSL is doing its job so far... #netsec

@mikeboers on . Visit on Twitter.

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