Fire jet 1 preset weird scaling when changing voxel count

A lot of people have said it before but the way voxel size and scaling works is very weird and counterintuitive. Amazing software otherwise though!

Anyway I’ve encountered a very strange problem that doesn’t seem to align with how Embergen is supposed to work.
I’m playing around with the fire jet 1 preset. When I increase the voxel count on one axis (e.g. Y 384 to 400) everything should stay the same except I get more voxels in that axis, right? Instead, when I click apply new resolution the whole bounding box scales like crazy relative to the shapes in the scene and the fire simulation appears completely different and tiny. Anybody know why that is? Only happens for some presets.


Hi Matthew,

Thanks for reaching out, have you updated EmberGen to 1.0.3? I believe we shipped some presets out with the launch of 1.0 with incorrect Simulation Size values. Essentially we changed the values in the Simulation node and didn’t hit the “Apply New Resolution” button before saving. *facepalm

We fixed this in 1.0.2 or 1.0.3, so if you update to the most recent version it should overwrite those presets. Let me know if that sounds like the issue you’re having.

I want to add to this to say that if you have 128x128x128 for example and a voxel size of 0.1 that will be a small box. If you change the size to 0.5 it will be much larger and 0.05 much smaller. The box size will NOT stay the same, but it makes sense because you’re telling it you want 128 voxels to be larger or smaller sizes and it will abide by that. If you are looking for more voxel density but keep the same size box, you would use upscaling x2, x3, or x4. I would recommend x2 or x3 anything more than that and you may run out of VRAM very fast.

As will mentioned though, in the lastest builds we fixed this weird bug with the fire presets.