"I’m Sorry Dave… I’m afraid you can’t do that."
by Simista on 25/10/2013
Hello CarmaFans, Sim here!
I Just thought I would share a little bit of good news on development side of things and also share something funny that happened during the week…
Little Bit of THIS – Mega Virtual Texturing News
First bit of grand news is that the texturing technique we are implementing – previously referred to by us non-tech types as Mega Texturing, but actually more accurately termed “Virtual Texturing” – should be finished “by the end of the week”… Which is actually around about… NOW. HORRAH!
This means that the lovely detailed environment work the artists have been doing that utilises this amazing technology will actually be visible on yer everyday decent PC, all around the office (and not just on super-powered throbbing shit hot art PCs), in a matter of days!
And what is Virtual Texturing, again? I asked our Head of Tech, Nick Slaven, for a description that even nobby would be able to understand. Nick replied, “Well strictly speaking it’s known as Sparse Virtual Texturing, and simply put it is the creation of large virtual textures that are streamed from disk. The mega texture system takes artist generated image data and chops it into many smaller texture pages that can be streamed off disk as needed. This will allow artists to create greater levels of texture detail within the scene than we’ve ever had before, and will speed up the loading times and keep memory usage low.
The texture pages are of fixed size, currently 128 by 128 pixels and the system currently supports a page array of 65536 by 65536, giving a virtual texture space of 8,388,608 by 8,388,608 pixels.
On our test levels only a fraction of this space is currently used, around 500 x 500 pages, this is still around 250,000 unique texture pages being generated occupying around 7 to 9 GBytes of disk space.
We’ve plenty of space for expansion, disk space permitting (if the whole virtual texture were filled, we wouldn’t actually be able to store it on current hardware… )”
GOOD STUFF EH ;) (But nobby looked like it made his head hurt, and had to have a lie down.) When he’d come to his senses again, he added, “So, every day we’re moving closer to a reveal of the work on the levels. The wait is as frustrating to us as it is to all of you out there, but that’s what happens when you’re re-writing the game core tech pretty much from scratch at the same time as developing the game itself. It’s all about ‘dependencies’, and we has them.” And to emphasise this, he booted a passing badger up the arse.
Little bit of THAT – Fun with Physics!
This week we got a really interesting email from the art team, entitled “Fun with Physics”.
I’m going to copy and paste the email here, but first I’ll give you a bit of information on what Dave is talking about.
In our Industrial level we have the basic shipping containers around a dock area, and there are also big machines like the one Tom Cruise drives in War of the Worlds, that pick up these containers and move them about. This helps to bring the environment to life, and will add some hazards for the player to have fun driving around in the level. The Email was about a bug that relates to these elements:
Most of you will have noticed by now the utter devastation of the containers in the dock area of industrial which occurs after about 3½ minutes.
I discovered what’s causing it yesterday evening (bear with me, there’s a bit of explanatory preamble).
It’s caused by the loader animation looping. The loader animation consists of the loader moving containers A and B around the yard.
In order to save on keyframes however, the animation isn’t a complete loop – at the end of the animation A and B have swapped places.
Visually this isn’t an issue as the containers look identical so the animation appears to loop seamlessly… until such time as the containers are given a mass less than infinity…
The start and end positions of containers A and B are some 300m apart and the animation runs at 30fps
This means that at the point the animation loops back to the start, these containers have to move 300m back to their starting positions in one thirtieth of a second
Which is 9km/s
Which is 32400km/h... just over Mach 33
By way of comparison:
- Velocity of Geostationary orbit - 11052 km/s
- Orbiting Velocity of International Space Station – 27,600 km/h
- Escape velocity on Earth – 40,320 km/h
It gets better…
Containers A and B have been given a mass of 100 metric tonnes (heavy enough not to be moved by collision)
So let’s consider the kinetic energy of a 100 tonne object moving at 9km/s
E = ½mv² = 50000 x 9000² = 4.05 trillion joules
Or to put it another way…
0.968 Megatons of explosive energy
If the container was spherical and hit the ground at a perpendicular angle the resulting crater would measure 189 metres across
Such is the accuracy of our physics that this kinetic energy in-game is enough to launch a 3 tonne container 500m….. Which I imagine is pretty much what happens when a nuclear bomb goes off in a dockyard.
So my fuckup qualifies as both astronomical and apocalyptic!
So thanks for sharing Dave! He quickly fixed the problem, BUT! We sneakily got hold of the offending buggy container Loader, and we have a cunning plan to stick it back in the level (or our test environment) and reproduce the outcome for all to see!
Of course, what this “Whoops!” moment emphasises is that this is exactly the kinda fun you will be able to have using CarMODgeddon, which will allow you to muck around with the parameters of all manner of in-game assets and also add your own, so you too can have Fun in the Stainless Playground of Physics™!
Now boot a badger up the bum… in celebration!
See ya soon Carmachums!