Tessellated multi-layer height map
This post describes a method for storing a very large landscape for a game world. A height map is the conventional method for representing topography in game environments. A height map is essentially a monochrome bitmap in which darker colours represent greater heights. This means the landscape architect can draw it easily in conventional bitmap editing tools, and it’s easy to convert into a three dimensional map which can be rendered, just by drawing vertices between adjacent points in the grid. However, if you use a height map for a game territory, then either you have a fairly constrained territory or else you don’t have much complex topology. I want a territory of at least a million square kilometres — that’s four times the area of Great Britain or three times the area of Germany.
Having topographical features only at the kilometer scale — a one thousand by one thousand array of heights — would produce a wholly unnatural landscape. Having topographical features on the metre scale would produce a much more natural landscape, but at the cost of a million by a million array, which pushes the storage capacity of current generation machines and thus leaves much less storage for the many other things I want to model.
One solution, if a height map is chosen as the preferred representation of topology, is to tessellate the height map. The problem with that is that sooner or later the player is going to think ‘I’ve seen this same landform before somewhere else’.
Turbine economics
Last week I had one of those experiences which felt at the time like small defeats but which actually are steps forward — although not necessarily in the direction I really want to go. Call it a tactical withdrawal. I moved my computer from the Winter Palace up to the Void. In the Void — the huge old cattle shed which forms the hub of our community-that-is-not-a-community — it can use mains power, rather than depending on my wind turbine. Also, it can use the landline broadband, rather than using my satellite connection. The truth is that at this time of year my wind turbine is not generating enough power for my day to day use, and as I am now running low on the money I earned last year and need to start looking for employment again, I need to use my computer (and the Internet) more.
So this is a post about the energy economics of living off grid.
This picture is illegal in Scotland
This picture is illegal in Scotland.
What! Why?
Against Land Value Tax
They've been in the family a long time. They were improved, it's true, by his ancestor Robert Grosvenor in the early nineteenth century. But essentially their current huge value is down to two things: first, the growth of London, to which the Grosvenors made no special contribution; and second, improvements in infrastructure — roads, railways, sewers and so on — that have been paid for out of the public purse.
This is the case for Land Value Tax. Landowners — like the Grosvenors — make windfall profits out of public works and out of pure luck. This is just one among many ways that the rich are rewarded purely as a result of being rich, and without making any reference to the desirability of the equable distribution of wealth there is a clear public interest in profits generated as a result of works paid for out of the public purse returning to the public purse.
Cycle helmets, and road safety: a letter to the Lord Advocate
I've written about cycling helmets and safety a couple of times before. See 'Using, not losing, your head', and 'Lies, damned lies, and cycle helmets'. But more often, as you know, I write about things which relate to public policy in Scotland. Now, sadly, I'm having to combine the two topics.
In brief, in August 2011 a driver named Gary McCourt mowed down a 75 year old cyclist, Audrey Fyfe, on the Portabello Road in Edinburgh. She was killed. Nor was this the first time that McCourt had mown down and killed a cyclist; in 1985 he had been jailed for killing 22 year old George Dalgity.
McCourt stood trial this month for the death of Audrey Fyfe. He was sentenced to 300 hours of community service, and banned from driving for five years. In passing this remarkably lenient sentence, Sheriff James Scott commented that Audrey Fyfe "...was not wearing a safety helmet and that in my view contributed to her death."