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Member Since 06 Sep 2000
Offline Last Active Nov 24 2014 05:27 PM

Posts I've Made

In Topic: photo renderer for unreal engine3

25 June 2014 - 12:47 PM

Well, what exactly do you need help with? What area are you having problems in?


It looks fantastic, btw. 


edit: Prematurely submitted.

In Topic: SNES Like 5 Layer 320x240 Graphics Library

25 March 2014 - 12:45 PM

The problem is that we DON'T understand what you wrote. Is this something you made? Is this just something you found and thought was cool and wanted to share?

What's the purpose? Is it supposed to be a SNES emulator running on the GPU? Etc?

In Topic: Moving Sphere vs Triangle Collision - Misunderstanding concepts!

30 January 2014 - 03:00 PM

If it's a moving sphere, you can just do ray->triangle intersections, and all you have to do is for each triangle, move the origin of the ray along the normal of the triangle by -radius.


Like this:


Sphere s(center, radius)


foreach(T in Triangles)


   if (s.touching(T))


      // Already touching the triangle...do whatever.




      Ray ray(s.center - (T.normal * s.radius), sphereDirection);

      if (ray.Intersect(T))


         CollisionPosition = ray.intersection;

         SpherePositionAtCollision = CollisionPosition + (T.normal * s.radius);





edit: I thought about this some more and I am wrong. This *does* do some of the work, but you still need to test the sphere against the triangle edges.

In Topic: How did 2D games handle this collision in antiquity?

09 January 2014 - 05:25 PM

Well, you could have the collision shape actually just be half the width of the sprite, but "slide" based on the direction the sprite is moving.


ie: For ground collisions, the collision shape is width/2, but one side is always at the center of the sprite, and the other side is opposite the direction of motion.

If no ground collision is detected, expand the shape to full width and test again, this way you can still handle edge cases when jumping/falling properly.


Does that sound like it should work?

In Topic: Give an example of specific values for b_1,b_2 and b_3 so that there is no so...

17 December 2013 - 06:53 PM

b_2 = 2*b_1 + b_3?


as for 'specific values', just pick anything that doesn't work....


b_2 = 0 or any negative number ( <= 0)...


b_1 = any positive (> 0) number....

b_3 = any positive (> 0) number....


Maybe I don't understand the question?