If you need more than one particle system, you have two options : either use a single ParticleContainer, or one per system. Send the age of each particle along with the position, and in the shaders, compute the UVs like we did for the 2D font tutorial. You can animate your particles’ texture with a texture atlas. This will make ParticleContainer be sorted, and the particles now display correctly*: Almost there, but there’s a problem…Īs explained in Tutorial 10, you need to sort semi-transparent objects from back to front for the blending to be correct.īool operatorcameradistance > that.cameradistance
Static const GLfloat g_vertex_buffer_data = Thanks to instancing, they will be shared by all particles. The VBO containing the 4 vertices of the particles. No index buffer, so it’s 6 vec3, which make 2 triangles, which make 1 quad.
One buffer for the vertices of the mesh. You have many, many options on what to put in each buffer. Some of them describe the particularities of each instance of the base mesh. Technically, it’s done via several buffers : “Instancing” means that we have a base mesh (in our case, a simple quad of 2 triangles), but many instances of this quad. In this tutorial, we’ll use the 3rd option, because it is a nice balance between performance and availability, and on top of that, it’s easy to add support for the first method once this one works. Not available on ALL computers, but a vast majority of them. Not in the scope of this tutorial, mostly because 50% of the computers don’t support this. Generate a single VBO with all the particles in them. There are many ways to do this here are three of them : Then you will draw the second billboard, and it will be the same.Ĭlearly, we need a way to draw all particles at the same time. This is a very bad idea, because this means that all your shiny GTX’ 512+ multiprocessors will all be dedicated to draw ONE quad (obviously, only one will be used, so that’s 99% efficiency loss). The first idea to draw many particles would be to use the previous tutorial’s code, and call glDrawArrays once for each particle. 
This tutorial will present ONE way to solve them there are many other possibilities. There are two major differences, though :īoth of these difference come with problems. Particles are very similar to 3D billboards.
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