# Rendering without fire when executed from command prompt

I am rendering from command prompt and output file is something like: expected:

I executed this command(My installation Directory):

set path="C:\Program Files\Blender 2.79\blender-2.79.0-git.ec20d311da4-windows64"


path to my .blend file:

cd desktop\blender projects


and then:

blender -b art.blend -E CYCLES -s 10 -e 10 -t 2 -a


And I have saved my file too.!

• Could it be because simulations are not parameterized animations and thus can not be computed at a certain frame without computing all the previous frames? I think simulation cache should solve this problem, but not sure how. – Omar Emara Mar 1 '19 at 13:41
• is the smoke simulation cache baked and saved? – user1853 Mar 3 '19 at 3:00
• @cegaton I never use baking because I don't know how to use it! – Yash Mar 3 '19 at 4:53
• @Yash the search box at the top is a good friend... – user1853 Mar 3 '19 at 6:06
• That's fine @cegaton but if you remember any question please link it! It would be helpful ;) – Yash Mar 3 '19 at 6:09

Smoke simulations need to be calculated in order to have something to display on render.
When using Blender, the calculations are being made as soon as you playback from the start frame or when you start a render.

But! When using command line rendering, the render command only does the rendering, not the smoke calculations. So before doing some command line rendering, you need to bake the smoke simulations, meaning you have to ask Blender to calculate the actual simulations and store the result into files, which will be later read when rendering. It's the way to go even with UI rendering anyway, as it's overall faster to bake then render instead of rendering and calculating the simulations on the fly, especially if you render it several times. And if gives more reliable results to have baked sims.

So basically, you just have to watch in your domain's parameters, in the Bake panel. Set the right Start and End frames, hit Bake All Dynamics, wait for it to bale everything (it might take a while) and save your file.

• So it is mandatory to bake before Rendering from command line for things like smoke simulation,etc? – Yash Mar 10 '19 at 18:05
• Looks like it is. And on a practical point of view, you should bake before rendering anyway. – L0Lock Mar 10 '19 at 20:56