I’m currently working on the CGi for a short steampunk film - most of it’s going ok, but i’m having an issue with the smoke and fire simulations. The issue is, I have a shot where an airship is hit by a shell - i’ve got the fire side of things and simulation working fine, but for some reason, the smoke is coming out so thin it barely shows up.
I’ve tried the obvious things, like increasing the smoke density (up to absurdly high values - in the billions), playing around with the resolution settings, changing the scene light settings etc, but no joy, What I need is really thick, billowing black smoke with a glimmer of a fireball in the centre - what annoys me is that i’ve got it working fairly well before in a previous film (see below), but I deleted the blend files in error when we finished the project.
Does anyone have any ideas? My gut says i’ve missed something stupid, but IDK for sure.
I’m using blender cycles 2.78b, with GPU render/Nvidia Geforce GTX950 card.
Previous film - explosions throughout, but about a good example about a minute in.
3 Frames after hit:
25 frames after hit (should be a mass of smoke by now)
Smoke domain material. Density is shown at 5 here, but I have tried it very high (billions +)with no useful effect:
It looks like you have density output going into the ‘Contrast’ input on the brightness/contrast. It should be going into the the Color input. The brightness and the contrast will get very touchy when the contrats is high. There will be some brightness value above hwich it’s thick, and below which is a big drop in appearent density. If the smoke is too thin, increase the brightness, and cotrast.
Thanks, that has made the smoke more visible - there’s still an issue though; although the flames are coming out in roughly the same place as they’re shown in the open GL renders, the smoke is dispersed across the entire domain - to give you an example, 11 frames after impact (I have scaled it down a bit):
Which says to me the true issue may be to do with the concentration of the smoke, as compared to its density - any thoughts? (And thanks for the advice)
Without the packed blend, hard to know. If you keep ticking up the contrast, often times you hit a threshold value where there’s a big jump (of less but harder edged smoke) so it’s like bright 2.0,contrast 1.5, smoke everywhere. bright 2.0, contrast 1.6, much less smoke. What I do sometime is shrink the viewport way down like 100 picle,s and keep it in rendered mode, and tweak the nodes until it looks good, then zoom in and let some samples pass to get a better idea.
That’s helped again, but still very dispersed smoke - i’ve attached the .blend file; sorry it’s a bit of a mess, it started off as a rough copy to get the smoke working. Explosion starts at frame 50; i’ve had to cut out a lot of the scene to reduce the file size as well i’m afraid.
Did anyone find time to take a look at this in the end? I’m still a bit flummoxed, as i’ve got similar simulations working well before - could it be a subtle change with the newer edition of blender?
It looks like you’re using particles for the smoke object, but your particles only have a lifetime of 1 frame. The particles turn from fire into smoke, but you don’t have enough time for them to do that. It appears that blender always uses some residual smoke and that’s the only thing that is left in your animation. I’ve done something like this before and I didn’t use particles, I just used an object and scaled it up for the explosion and shrunk it down to almost nothing for some residual smoke. However the best way to do it is to have two objects or particle systems. One for the explosion and one for the residual smoke effect you want.
