Also, some per-voxel noise is added to cover up this effect (and make it look nicer I think). You can disable this in the fragment shader.

The two-pass removing of voxels is because each voxel checks its neighbours to decide whether to spawn a cube when it is destroyed. That is, we only spawn cubes for surface voxels. But deleting voxels may make previously hidden voxels now become surface voxels. so the first pass identifies all surface voxels in range of the explosion, and the second pass deletes all voxels in range of the explosion and spawns cubes for the previously-identified surface voxels. I hope that is clear?

I think cellular automata approaches should be possible but the memory leaks will have to be fixed first. I hope to get the free version in the asset store by the end of the year (hopefully sooner, depends how much polish we add!).

I’m setting the alpha value correctly (to 255) and I tried to use the blue value to indicate water content of a cell. So 0 is no water and 255 is full of water.

The bug seems to be that setting the blue content to a byte value less than 255 does not work correctly. Often it seems to set the value to a lower number… is there some compression or something going on with the color values that could cause this? It’s hard to tell without having access to the engine code. I tried cellular automata approaches on existing voxels and setting new ones, and found the same problem either way. In the end I literally wrote code that set the color value and immediately read it back, discovering that it had changed and was not set correctly hence my suspicion that this is an engine problem.

I notice in your code you add all the particles you want to remove to a list and then remove them later and I wondered if that was too avoid an issue like this? I assume your plan is for the engine to allow users to write cellular automata code for simulations like Minecraft lava?

I ran into the memory problems too (Unity crashed a few times).

Any idea when you plan to make a proper release?

Keep up the great work! 🙂

When you say the color has to be 255, do you mean the alpha? The system does not (currently) support transparency so alpha value must be zero or 255. The alpha channel is present in case we support transparency in the future, but we should add a warning to stop people using it now.

There are known memory leaks when modifying the terrain, so if you are modifying every frame (for water simulation) then there may be memory errors. We have to fix these leaks before making a proper release.

For water simulation could you consider particle-based fluids (e.g. using Fluvio for Unity) and then drawing each particle as a cube snapped to the nearest integer position in the vertex shader? This might be an interesting alternative to cellular automata based approaches (though I haven’t tried it).

Glad you like the project anyway 🙂

There is no real timescale for a finished version of the library. Instead, we intend to make an alpha version publicly available in the coming few weeks, and then continue to develop it in public view. People can simply purchase a license once they feel it is becoming useful to them.

There will always be a free version with limited terrain size. Support for larger terrain will cost about a few hundred USD, though the exact available sizes and price points are not finalised yet.