Keywords: Direct volume rendering, texture mapping, splatting, ray marching, octree, kd-tree, memory management, GPU.

There’s also a PDF version available.

I’m providing this material because I think this is useful for other people interested in the subject. You won’t find any PhD-critical info, of course

This week, I’m putting a stop to this. No more coke, and once I’m completely detoxed, we’ll see what my weekly intake should be. That is, if I don’t fail. I’m quitting because I consumed too much sugar, and my PhD research is mostly done sitting at a desk. In comes the fat! Also, lowering my cafeine dependency to actually be awake in the morning could be helpful. Mind you; a lot of criticism and health effects you believe are true about coca-cola, are not.

I guess I did it for the lulz.

I’ll say it again: the unnecessary customizations vendors are pushing onto Android phones is what really irritates me. Motorola came up with a network called MotoBlur. Sigh.

Vendors, I don’t want to create an account on your private cloud and link my phone to your little part of the web forever. It’s a good thing that Google’s now requiring the default Holo theme for vendor phones with ICS.

Anyhow, here’s how it went. My phone came with Gingerbread 2.3.4, and a carrier firmware version 2.3.4-4.5.2A-74_OLE-25. Instructions behind the cut!

Unlocking: A first dissapointment

If you’re in a hurry, you can skip this section.

Mind you: I bought the international version of the phone, so it wasn’t locked to a specific network, but the bootloader itself was locked – I had to unlock it in order to be able to install ClockworkMod Recovery (or any other custom recovery). Anyhow, I thought this would be a breeze, since Motorola released an unlockable bootloader with the Gingerbread update, Unfortunately, the firmware version that came with my device (2.3.4-4.5.2A-74_OLE-25) did not support it, which I thought was weird. (edit: After some googling, it seems they had the unlock in place for 2.3.3, but disabled it again for 2.3.4. FlipFloppers.)

When I connected to the phone via fastboot and did a fastboot oem unlock, I got this result:

... INFOOEM unlock is not implemented
OKAY [  0.001s]

If you get a similar result, you can be pretty sure your stock bootloader is not unlockable. I used this fastboot distribution, but any fastboot install (from the Android SDK, for example) will do.

When I tried to install an official update (I thought it would give me a new bootloader) by registering with Motoblur and using the update functionality in the original distribution, it would download the update, but after that, the phone just kept rebooting and the screen said:

Boot failed 2
Starting RDS Protocol ...

Pulling the battery and powering it back up would boot me into Android again, which would then immediately restart to apply the update again. Great job Motorola, even your official updates make my device bootloop. Luckily, I could fix this annoying behaviour by doing a fastboot wipe of cache and user data (essentially resetting the phone to factory state):

fastboot -w

Unlocking: This time, we do it right

So yes, it was time to hit the XDA Developer forums, looking for a way to unlock the bootloader. Since most of the guides and auto-tools were for AT&T phones, I had to find a way to do it for international phones.

It was time to get dirty with SBF’s, which are Single Binary Files. It’s Motorola’s proprietary way of flashing new firmware. You can seriously brick your phone if you don’t know what you’re doing with this – double check the instructions in the relevant XDA threads if you’re unsure about something. This is an excellent starting point, although mainly oriented on AT&T users.

After a bit of research, I ended up following this thread, and did all the unlocking/rooting on a Windows XP SP3 32-bit installation. Any recent windows version should do, though.

Download the following:

• Motorola Android Drivers
• RSDLite: Google for RSD Lite 5.5 or more (here, for example).
• The IHOP/Bell SBF file from this thread
• A Fastboot package (for example, from here, or from the android SDK)

As some of you noticed, this guide pretty much tells the same story and has all the downloads handy in place – your pick!

Here we go. As always: I’m not responsible for any damage, yada yada. We’re well beyond safe waters here, but as long as you follow the instructions carefully and don’t panic (NEVER pull a battery whilst flashing an SBF), it will be fine.

• Make sure your phone is plugged in / fully charged, and if you’re using a laptop, make sure it has got power too.
• Power off the phone.
• Power it back up again whilst holding the power and the volume up button.
• The screen will display: Starting RDS protocol
• You can release the buttons now
• Run RSD Lite on your computer
• Click open and browse to the downloaded SBF file (which you have unzipped)
• Plug in your phone using the USB cable. In RSDLite, it should show up as “Model: NS Flash Olympus”, and should say “Connected”.
• If it doesn’t, the Motorola Drivers were not correctly installed – reinstall them or reboot your pc.
• Hit start. Don’t touch the phone.This can take a while (about 2/3 minutes in my case)
• The phone will reboot automatically.
• Open the windows command (start->run->type “cmd”) prompt and navigate to the place where you unzipped the fastboot package. It’s probably easiest if you unzip it in C:/fastboot. You can navigate to that directory by using (where cd stands for “Change Directory”):
• cd C:/fastboot
• If you don’t manage to get into the right directory, you can always use auto-completion (TAB) to make the cmd prompt help you to form the correct command.
• Power off the phone
• Connect it to the computer
• Power it back up again whilst holding the power and volume down button (mind you: it’s the down button now)
• Hold it until you see “fastboot” on the screen
• Click the power up button once, to start fastboot mode.
• In the windows command prompt, you can issue the following commands. if they don’t get recognized, you have not navigated to your fastboot directory correctly:
• fastboot oem unlock
• You’ll see a warning and a Device ID. Copy it, or write it down somewhere, then issue the following command, while inserting the device id at the indicated place:
• fastboot oem unlock <deviceid>
• You’ll get a “Congratulations, your phone is unlocked” message
• fastboot reboot
• Phone will reboot.

If any of the above steps don’t work, you can verify the following:

• Have you installed the Motorola drivers correctly? (Might be required to reboot after you installed them)
• Are you using an RSDLite version > 5.x ? (This is a requirement)
• Did you press the correct button combinations? Can be confusing sometimes

Rooting

Woojay, unlocked! Now what’s next? If we root the Atrix, we can install a custom recovery to our newly unlocked bootloader and start flashing new ROM’s, as well as taking a complete backup of the current one.

There’s an excellent one-click-root method available here for 2.3.4 ROMs. This is the one I’ve used. Make sure your phone is in charge-only mode. I had to retry it a couple of times (2 / 3), but it did work eventually. Don’t worry, it’s pretty safe. The Atrix is mentioned nowhere on the tool’s page, but it does work. An alternative is: this thread, but I haven’t tried that one.

I’m not going to repeat the steps here: it’s basicly : unzip the tool, connect the phone, make sure it’s in USB debugging mode (settings->applications->development settings->enable debugging mode) and run the tool.

Installing ClockWorkMod Recovery

After you’ve rooted and rebooted, it’s time to install a ClockWorkMod Recovery. This is an excellent tool. It’s a mini-os which you can start when the phone boots, which allows you to flash custom ROMS, take backups and much more!

• Go to the Android market and download ROM Manager
• Open ROM Manager, and use the top item: Flash ClockWorkMod Recovery
• Select Atrix from the list
• It will flash the default CWM Recovery now
• For Atrix, there’s a better recovery available: Romracer’s CWM
• Download your favorite flavor (it comes in several colors) it and place it on your sdcard.
• In ROM Manager, select Install Rom From SD-Card, and browse to the zip file you downloaded.
• The phone will reboot and replace the default recovery with the Romracer’s Recovery.

Installing a custom ROM (Cyanogenmod 7)

Yay, home-free! I’ll refer to this excellent guide for flashing Cyanogenmod 7: Another good resource for all things Atrix is this thread and the XDA forum itself, of course.

Have fun!

Read up a bit on TOR (The Onion Router), adn then watch the video embedded below. Don’t stop there though – donate some money to the project, help out in the development and/or set up your own TOR relay!

Sampling all geometric and texture data on a regular grid allows for unique content, theoretically. No more repeating textures, pieces of scenery, … artists can basically create a scene and add little customizations to every object, without sacrificing rendering budget, as long as you’ve got a good way of streaming the right data to the GPU. Interesting work is done by Cyril Crassin on Gigavoxels, a paper which shows a working implementation of the Voxels-in-a-tree concept.

I think it’s a nice way to introduce some kind of ray casting (and all the benefits it brings) into a modern-day real-time graphics pipeline, instead of the traditional way of splatting polygons down on a canvas and using several shaders to fake effects which are gained automatically when shooting rays. It would also simplify a lot of algorithms if you can treat geometry and (for example) texture information as being on the same grid and resolution.

In 2011, Nvidia research also published a paper on Sparse Voxel Octrees (link), following a demo on I3D. Some of the code was published here. Interesting read!

Also, a quote from Carmack in a recent interview on ID Tech 6:

 It’s interesting in that the algorithms would be something that, it’s almost unfortunate in the aspect that these algorithms would take great advantage of simpler bit-level operations in many cases and they would wind up being implemented on this 32-bit floating point operation-based hardware.  Hardware designed specifically for sparse voxel ray casting would be much smaller and simpler and faster than a general purpose solution

Getting started

There are several ways to update, but for small to medium projects, I found it best to just unzip the new CakePHP 2 structure, and manually copy over your Controllers and Views to their new folders. Mind you that the folder structure has changed significantly. For instance, the controllers map is now Controller. Pay attention to where you copy the files – don’t worry about the filenames themselves, we’ll come to that later.

Make sure you update core.php and database.php (now located in (cakephp root)/app/Config) with the values for your application. Make sure to copy over the salt and cipherseed values from your old installation too, since CakePHP will continue whining when you use the default ones – it’s a security risk. Also, to get the database connection up and running again, the syntax was changed:

'driver' => 'mysqli'

becomes

'datasource' => 'Database/Mysql'

Bulk work: Upgrade via console

In order to rename all your app files to the new CakePHP file structure, there is a console command. New to CakePHP 2.0 is that each application now has its own console. Navigate to your app’s console (not the Console in /lib/Cake !) in /app/Console, make sure the Console command is executable by doing a chmod +x on it, and execute:

./cake upgrade all

This will rename all files to the new cake standard, and update all references within your PHP code.

Cleaning Up

Unfortunately, this is not the end. Chances are thin that your code will just run fine now. Have a look at the CakePHP 2.0 migration guide for more information. I’ll sum up the issues I’ve dealt with the most here:

• In your views, you now have to address the Helper classes through the $this object. No more calling, for example $html->link( , it’s $this->Html->link( now, sir.
• The JavascriptHelper is now called JsHelper.
• The Auth component has changed significantly. The login() action is not automatically added when you use the component, you’ve got to manually specify it now. Check the new Auth component documentation for more info.
• The AjaxHelper has been removed, along with the handy functions for AJAX-style searches, like observefield. I’ve cooked my own observefield using jQuery – use at your own risk. I serialise a form, which in this case holds a query input box which allows me to do a live-search-and-update for Reservations :

$this->Js->get('#query')->event('keyup', $this->Js->request(
array('controller' => 'sales','action' => 'searchReservations', $event['Event']['id']),
array(
'update' => '#view',
'async' => true,
'dataExpression' => true,
'method' => 'post',
'data' => $this->Js->serializeForm(array('isForm' => false, 'inline' => true))) 



]]> http://www.forceflow.be/2011/11/12/migrating-from-cakephp-1-3-to-2-0/feed/ 0 http://www.forceflow.be/2011/10/26/game-graphics-tech-talks/ http://www.forceflow.be/2011/10/26/game-graphics-tech-talks/#comments Wed, 26 Oct 2011 13:18:15 +0000 Jeroen http://www.forceflow.be/?p=1931 Continue reading →]]> Here’s some recent game graphics talks I’ve been enjoying.

First one is Carmack on Quakecon 2011 – it’s a very technical talk, but very interesting on how they do texture streaming on consoles, compared to pc systems.

Here’s the Q&A section, which is even more technical, but contains some interesting question on id’s coding style.

More recently, here’s DICE’s Johan Andersson talking about the graphics technology in Battlefield 3, which seems to be a perfected deferred-shading pipeline. It’s interesting to see which decisions they made in order to have certain effects stand out, and how they calculate the rendering budget for each scene. Talk starts of a bit generalised, but once you get to parts 2 and 3 he goes into more detail.



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