So last time, I had managed to add some code to create a height-map from a simplex noise function, using the space coordinates as input and getting a pseudo-random number between -1 and 1 as the output. For now I'm just coloring the vertices, black for lowest value and white for highest, but eventually I'd use the values to distort the sphere.
The only problem was that the noise function used a shuffled array to create the pattern of noise, so in order to create new patterns I had to reshuffle that array. Reshuffling the array presented a few problems, mostly caused by my reliance on the STL's rand() function, which is really quite terrible. As a result I had to search for a better function that could do the job I needed.
I eventually found an excellent paper on pseudo random number generators, by David Jones. I settled for the JLKISS64 generator, and after altering it to fit the framework I managed to create multiple height maps on demand. The problem, then, was how to display them.
Currently, my method for displaying models is to create a Vertex Buffer Array for each model, and a custom transform for each object. The different spheres where really all the same array with different matrices applied. But the height map was created as an additional coloring at each vertex, meaning I had to create new Arrays that still used the same buffers for vertex position, normal and color, but different heights.
This was fairly straightforward, thankfully. Essentially, the process involved the same steps as creating a vertex array from scratch, but skipping the buffer step, since the information had already been loaded to the video card.
In short order I had the new code running, and the space that was once filled with the same patterned spheres now had unique marbles floating all about.
Next up, I'm going to be trying to get text into the program, create a console of sorts.
Monday, January 16, 2012
Thursday, January 12, 2012
Game releases, coder's block and family obligations kept me pretty busy the past few weeks. However that is all behind us now, and I'm back in business. I've even done some progress, and should have a new demo on Monday. Nothing special, except that each and every asteroid is now unique. I'm looking into how to get writing in the game, now. That might not make it into the next release, but should fit in the following one for sure.