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Once upon a time, a friend of mine gave some of us a challenge. It's not exactly the same but quite similar ;) Anyway, think of ways you can generate alternating 0 and 1. If you have an Update() loop, the first time you call update it will generate 0 and the next time will be 1, and then 0,1,0,1,.. you get the idea. I found 3 ways to do this (assuming initial value of i is 0). Math + Bit i = (i+1) & 1; // You might think of this i = (i+1) % 2. Simple Math i = 1 - i; Bits Operations i = i ^ 1; Can you come up with more ways?

Depending on which platform and target hardware, it can be a good idea to eliminate branches in shader. Here's two techniques with samples. Lerp Lerp, a.k.a. linear interpolation, is a useful function to select between two things. If you have two vectors v1, v2 and you want to select one of them based on some condition, lerp can be used. Make sure that the result of the condition (conditionMask)  is always 0 or 1.  You can then do this: result = lerp(v1, v2, conditionMask); If your condition is 0, it will return v1. If your condition is 1, it will return v2. Min/Max Min and max is very useful in some cases. For example, let say you want to have one shader to switch between lit and not-lit. Typically, we will multiply the lighting value with color. For instance: light = CalcLighting(); color *= light; So, the condition would be, if there's no lighting return 1; otherwise return the lighting value. We can easily do this with Lerp. light = lerp(1, CalcLighting(), isLi...

There are many ways to read/parse XML with Python.  I found at least 2 methods: DOM and SAX. Document Object Model (DOM) is a cross-language API from W3C for accessing or modifying XML; whereas SAX stands for Simple API for XML. Most of the time, we don't need to understand the whole XML vocabularies; and most of the time we want to parse simple stuff like: <root> <person name="somebody"></person> <person name="otherguy"></person> </root> I think the simplest way to go is to use python minidom implementation that looks like this: from xml.dom import minidom # parse the xml theXml = minidom.parse('data.xml') # iterate through the root rootList = theXml.getElementsByTagName('root') for root in rootList: # you can get the element name by: root.localName # iterate through person personList = root.getElementsByTagName('person') for person in personList: # get the att...