Indy Telecom & Industrial Media

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So, here is a brief overview of the problems I had in installing Beryl on Edgy on my Dell e1405 with an Intel chipset. I figured this information might be useful for folks that might do some searching later.

• For starters, I used the information from the Beryl project’s wiki page for Edgy as the base-line to begin from.

• The default video driver that Edgy comes with seems to have problem, and for whatever reason, I had nvidia’s glx drivers installed. So, I did the following (without X running):

sudo apt-get remove --purge nvidia-glx
sudo apt-get remove --purge xserver-xorg-video-i810
sudo apt-get install xserver-xorg-video-i810


• After this, I tried running glxgears and while it ran, it was quite choppy and was being rendered indirectly.

• This, as it turns out, was because the installation procedure overwrites a version of libgl-mesa that has conflicts with the drivers. So, I installed the latest libgl-mesa driver:sudo apt-get install libgl1-mesa-dri

• After this, I installed beryl using sudo apt-get install beryl and beryl-manager using sudo apt-get install beryl-manager and everything seems to work fine.

I did find a couple of other bugs, however:

• Having gnome’s screensaver on seems to hang X. So, if your screensaver hangs, you can either revert to Xscreensaver or turn it off. There are plenty of threads on Ubuntuforums discussing this.

• The System > Quit -> [Hibernate/Sleep/Reboot/Login/Switch User/Shutdown] options disappear, and clicking on the System -> Quit icon seems to reboot.

Turns out that both of these are bugs acknowledged by the Beryl project, so you’d just have to wait until these are solved. For the moment, for the first bug, I do not really care since I do not use screensavers. As far as the second one is concerned, I revert back to Metacity and then everything works fine. When I get back, I just start Beryl up again.

So far, I am loving it! I have an Intel Centrino Duo notebook with an i810 chipset (with an Intel 950 GMA) and 1 GB HDD. Nothing spectacular, yet with all the special effects on, Beryl is a breeze – I haven’t noticed any discernible drop in performance in any way. If anything, I find myself way more productive.

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The usual immersion of this surface is given by the equation:

The famous “figure 8” immersion can be expressed in parametric equations as:

[Mimetex cannot convert this formula]

[Mimetex cannot convert this formula]

The renders shown below are of the latter, done in Scilab. Click to view the larger versions.

And as always, here is the code for the above render:

//Klein Bottle
clear;
stacksize (10000000);
num_points = 50;
u = linspace (0, 2*(%pi), num_points);
v= linspace (0, 2*(%pi), num_points);
[U, V] = meshgrid (u, v);
x = cos(U).*(cos(U./2).*(sqrt(2)+cos(V))+(sin(U./2).*sin(V).*cos(V)));
y = sin(U).*(cos(U./2).*(sqrt(2)+cos(V))+(sin(U./2).*sin(V).*cos(V)));
z = -1.*sin(U./2).*(sqrt(2)+cos(V))+cos(U./2).*sin(V).*cos(V);
surf(x, y, z,’edgecol’,'gre’);

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The homotopy between a Roman surface and a Boy surface can be given by the following equations [1]:

for u [-PI/2, PI/2] and v [0, PI] and alpha varies from 0 (Roman surface) through 1 (Boy surface).

The following figures show the transformation between the two:

And here is the code for generating this (you can also use this to render an animation).

clear;
stacksize (10000000);
num_points = 50;
u = linspace (-%pi/2, %pi/2, num_points);
v= linspace (0, %pi, num_points);
[U, V] = meshgrid (u, v);
//alpha = 0: Roman surface; alpha = 1: Boy surface;
alpha = linspace(0, 1, 25);
for i = 1:length(alpha)
x = ((sqrt(2).*cos(2*U).*cos(V).*cos(V))+cos(U).*sin(2*V))./(2-alpha(i).*sqrt(2).*sin(3*U).*sin(2*V));
y = ((sqrt(2).*sin(2*U).*cos(V).*cos(V))-sin(U).*sin(2*V))./(2-alpha(i).*sqrt(2).*sin(3*U).*sin(2*V));
z = (3*cos(V).*cos(V))./(2-alpha(i)*sqrt(2).*sin(3*U)*sin(2*V));
surf(x, y, z,’edgecol’,'gre’);
end

[1] Courtesy: Roman surface (Mathworld)

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//Riemann sphere

clear;
stacksize (10000000);
num_points = 50;

u = linspace (-1, 1, num_points);
v = linspace (0, %pi, num_points);
[U, V] = meshgrid (u, v);

a = 1;
b = sqrt(1 + (a.*U).^2);

x = sin(U + V)./b;
y = cos(U + V)./b;
z = -a.*U./b;

surf(x, y, z,’edgecol’,'gre’);

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