Almost Done

Got some proper colour and size variables in there now so it can be changed! I've also changed the velocity texture to a 64bit one (R16G16B16A16) . I've tried the engine with a 1024 x 1024 texture which equates to 1,048,576 particles, it runs, but not smoothly, and a 768 x 768 texture (589,824 particles) which runs fairly smoothly. Its not limited to textures of sizes to the power of 2, its just the numbers I keep choosing out of habit. It all coming together, heres a video:

Pixel Shader Particle Engine

I've finally got my pixel shader particle engine working. Its by no where near finished but its getting there. The position and velocity data for each particle are stored in 128bit (R32G32B32A32) floating point textures, though I may change the velocity one to 64bit as 128bit is overkill. To get some randomness to the particles, on initialisation I create a 128 x 128, or 256 x 256 etc. pixel texture and fill it with random floating point values between -0.5 and 0.5. Particle velocty is then calculated by adding a set velocity value to a velocity variance multiplied by the value stored in the random texture:

final velocity = initial velocity + (velocity variance * random value)

As I am storing particle velocity and position in a texture, the particle engine is not stateless, meaning that I can (and have) implemented varying acceleration. At the minute there is just a bit of gravity or any other linear force in there, but eventually I sould be able to achieve such effects as vortexes. I can also add some sort of collision detection if desired, entirely on the GPU.

Im using vertex texture fetching to get the position data in the effect that presents the particles to the screen. This involves creating a list of verts (one for each particle) then using these vert as texture coordinate to sample the position texture. I still eed to get different colours and sizes in there but thats just a matter of adding another 2 parameters to the a vertex decleration and filling it in.

Below is a picture of it in action, Im storing particle data in a 512 x 512 pixel texture, meaning there is a total of 262,144 particles on screen. Quite a few more than my CPU based engine!

Solar Flux

Here is an early video of the game we are working on for our team project module. It is a space shooter, where the player can play from one of three camera angles. I've been working on the effects and shaders, at this minute we have the basic stuff in, like normal mapping and various specular lighting models, Phong (& Blinn), Ashikhmin etc. We also have HDR lighting in there, motion blur, various colour and film grain filters, radial blur, bloom (for computers that cant handle the HDR) and I've just managed to get DoF in there too, but its not demonstated in this video. I'll hopefully soon have some variance shadow mapping in there too.

3D Modeling with Blender

Recently I've been teaching myself to use the 3D modeling application known as Blender. Its a freeware alternative to the likes of 3D Studio Max and Softimage XSI. I have never done any 3D modeling before so this is my first attempt. Anyway, Ive made a little scene, here it is: