SPS Particle Depth Sort

[jerome]

As you know, the SPS is a standard mesh.

Applying the transparency to a standard mesh leads to well-known issues ... not when visualizing other opaque or transparent meshes through this current transparent mesh, but when visualizing some parts of this transparent mesh through itself. Indeed, when passing the mesh geometry to the GPU, this one draws the mesh in the order the mesh facets are sorted in the indices array : first triangle, second one, etc ... whatever the position of the camera. The shader only respects the geometry order and this geometry is fixed.

As the SPS is a standard mesh, it has the same issue when dealing with transparent particles (rotate the camera) : http://playground.babylonjs.com/#EPBTB7#3

A new feature allows now to sort the internal mesh geometry live according to the current camera position : http://playground.babylonjs.com/#EPBTB7#2

It sorts the SPS particles only, not all the facets, for performance reasons.

To enable it, just create your SPS with the parameter enableDepthSort to true. By default, each next call to setParticles() will sort the particles according to the camera global position.

If for some reasons (immobile camera and sps),  you want to stop (or reactivate) the sort on the next calls to setParticles(), just set the property sps.depthSortParticles to false (or true to reactivate it)

// create a particle depth sort enabled SPS
var sps = new BABYLON.SolidParticleSystem("sps", scene, {enableDepthSort: true});

// then later, only do ...
sps.setParticles();   // and the particle are depth sorted each call

// We can skip the sorting at any time (or reactive it) : sps and camera not moving anymore
sps.depthSortParticles = false;  // true by default when enableDepthSort is set to true

initial post :

Documentation coming soon ...

[GameMonetize]

This is.....HUGE

[jerome]

documented. (documentation / overviews / SPS)