• Create Account

# Uthman

Member Since 11 Jan 2000
Offline Last Active Jun 05 2015 12:30 PM

### In Topic: N64 Quality Water...

17 October 2011 - 08:35 AM

Here's a description of what we used to do back in the old days.
http://freespace.vir...ics/x_water.htm
When you've got it working you can just write some values into the current buffer for each position where you want objects to interact with the water.
This method is still used for games today when you need to get the water to ripple around objects.

o daaaaaaaamn, i havent been to that site in hella long ;-) I used to live on that site and other similar sites back in 2003-2005'ish. Talk about a blast from the past ;-] I learned how to draw lines, polygons, and do perlin noise off of that site. And their star field tutorial is still the best on the internet.

### In Topic: So who is still around these days?

25 September 2011 - 03:40 PM

boolean / fablefox i remember you guys =]

### In Topic: Space craft autopilot - physics question on turning acceleration/decelleration

09 April 2011 - 12:18 AM

spring forces

#define targetAngle 10.0f

// every physics time step
float dif = targetAngle - angle;
angle += dif * dampFactor;

### In Topic: electric field due to a line of charge

01 April 2011 - 07:45 AM

Hi Emergent,

It seems that I cannot effectively use Gauss' law on this one because of the major constraint that this is for a finite length line of charge. It does not have the symmetry required in order to use Gauss effectively (infinite length cylinder, sphere for point charge, etc.) Edge effects from the electric field about its endpoints would arise and the field will not be perpendicular to the line of charge, rather it would be bent in towards the endpoints. The Gaussian surface would need to be either parallel or orthogonal (for higher dimensions) to the electric field at all points. Because of this, integration is necessary and I have to stick to Coulomb's =T

### In Topic: electric field due to a line of charge

31 March 2011 - 11:43 PM

Hi jpmcmu,

First, thanks for the reply; I've posted this question on a physics form twice and I didn't even get a single reply... so I really need all the help I can get!

I followed your example--but it seems that your solution is the same as the first example in my image -- the text book solution, which I am able to solve already. Even though I wrote down the sin and cosine, I don't actually integrate over the angle. Rather, I use the geometry and pythagorean formulas to substitute for x*xhat and h*hhat, and then do the integration. This result I am sure is correct. What I'm confused about is parameterizing the line as a function of 't'. Once I do this and integrate, the answer I get doesn't match the popular / accepted text book solution that you described... yet I can't figure out where I erred. Help!

PARTNERS