smoke textures

Back on creating textures. First, I finished the first version of that new renderer. Might still have some bug, but in general, it's done.

One of the objectives that we had with this new tool that we created was to create some smoke. A bit similar to this one:

The picture above is called Smoke Art, so creating images using smoke. This one is not generated by any computer. Other Smoke Art are listed there: http://www.bablotech.com/2008/12/14/20-amazing-smoke-art-pictures/, and some of them are really amazing.

With our new method, we try to reproduce such piece of art, but completely random. We don't try to recreate a scene or anything. Just create random smoke effects.

There's many ways to do such images, the most popular is probably with particles. You use thousands or millions of points and let them behave like smoke. But this approach is heavy to run and it's mostly for animation. For static images like ours, it's not very interesting to manage that amount of points to finally find the right image.

Our method still consists of placing points and some information of associated with points on the plane to partition it. We are still using the layers to create the effects and it works really well with smoke. So here's some of my favorite that I created today:

We still have some work to do to really control that new technique. And also some experimentation to be sure that the behavior is more stable. One thing that we might try is adding a bit of color to it instead of working in gray. But not drastic colors like red or green. Little variation from gray, but enough to see that there's more.

Please leave any comment or question that you have about these textures.

first pattern

So, yesterday I mentioned two steps that we need to work on to finish the hierarchy project. And one of them is to work on patterns or structures to show what is possible to do with that product.

Today, I managed to to a first structure, a flower. Very simple to do. Just needed some adjustment first, but I got that result in few minutes. So here it is:

Naturally, I just showed the final product. I had other images created before I managed to do the right effect that I wanted. I think that this is a nice preview of what that product can do.

Let me know what you think about that output!

Hierarchy textures

So, it's been a while. I was so busy at SIGGRAPH that I never had the time to share anything.

In this post, I'm showing you some of the last textures I've been working on. These are build as a hierarchy. We use again our variation of the Voronoi diagram to create weird shapes. But this time, instead of using simply one level, we introduce many levels.

On the first level, again, the Voronoi cells are computed and once we know in which cell we are, if that cell has a sub-level, we can then continue the visit in the structure into that sub-level. Each level has can have a small or big influence on the final color of the pixel.

So, here's some outputs:

One of the first output made. It has two cells on the first level. One is the circle-like shape in the middle and then the rest. In the "rest", there's a sub level with a simple small division of the plane in two.

Exactly as the previous one, but here, there's a sub-level in the circle-like shape. As you can see, the fact that there's a new sub-level only affects the part where that sub-level is.

The actual first output that I got with the hierarchy.

In the next images, I start playing with colors inside the cells. Naturally, all of these images where made from random point distribution.

In these images, I simply played with the hierarchy. Each cell has a random chance to get a sub-level and so on. Until a maximal depth was reached. In some of them, I played also with the feature that at each level, you can influence the final color by accumulating a value.

Finally, there's two big step to do before we consider that project finished. First, we want to investigate various patterns. So, how can we do a particular shape for a cell. For this part, we don't need the hierarchy because we know it works. When we are able to control properly the patterns, we will be able to used them at various level.

Second, we want to be more dynamic for the color. Right now, each cell use a function f:[0;1]->[0;1] to control its value that will influence all the other levels. But those functions are a bit static. I can add more, but it will never be enough. So we turn to use something like the shaders in OpenGL. Literally, each cell could have its own function (coded in CUDA-C) and that function would be used to control the contribution of that cell and its sub-level to the final color of the pixel.