Blender Cycles Rendering problems

Hello Fello, Blender benders. Im new here and quite new to blender, the past month I’m working on a smoke simulation and when I got to texturing and rendering the smoke looks all blocky and pixelated, I can see the layers even tho I tried to max everything that I knew. But Im pretty sure I’m just missing something simple that I just don’t understand, maybe someone has some experience with Smoke simulation render ?

I added some pictures with work process where you can see what’s the problem.

Here are the Nodes if it gives some more info…

That looks like low smoke resolution to me. You see the individual voxels of your volume.
Try rebake your smoke simulation with higher resolution divisions.

Also cranking up your smoke density - like you did with muliply node will always reveal tiniest detail in your smoke, and with that will also reveal voxels which you can see on your smoke.

With higher resolution divisions you will see the detail but you wont see the voxels.
Bear in mind that changing smoke resolution will also change smoke overall shape.

Hello Silex, thank you for your response.
The Devisions I have right now are 250.
Will bake over night on 350 will see it it helps.

Another question, is how could I get the render time down, without losing the quality, or is it a smokers life and I have to deal with it and invest in a heavy render render machine.

250 is already pretty high. If you want to test if this is the culprit do a quick bake with lower resolution - if the voxels get bigger it means your problem is due to low resolution. This way it will take less time. Also for testing purposes with 350 res do only couple frames instead whole animation. That can save a lot testing time.

As for rendering it’s really hard to tell without all the settings and hardware specs.

Yes, I thought that its high. well anyway here is a fast 350 divisions, and I still see Them voxels… and some other greyish colours.
Path tracing is not finished in this one, but from experience I think it will not change the whole look a lot.

P.S. Here are the Specs. But I can get a little faster machine that would not change a lot.
From all the YouTube tuts, it should be possible to render this type of sim in good quality.

Screenshot 2021-01-22 at 23.37.28

If you want to make objective comparison between two smoke settings - render exact same frame of your animation from the same camera view. It’s hard to tell, if there is any difference if you are zooming in and out and moving scene in viewport.
If the voxels are visible from the beginning of the rendering, higher rendering samples wont do much beside wasting your time. For test rendering lower your samples, so you can make faster comparisons. Also dont render only in viewport - that is for real-time work. Render with F12 and save and name your tests renders. That will allow you to track changes in smoke settings.

Your CPU and GPU are midrange (in terms of raw compute power for todays standard). Also I’d argue against using any hardware with poor ventilation for long time rendering. Generally with poor heat dissipation your hardware will throttle and your rendering times will be much longer.

That said - try to optimise your rendering settings for your hardware setup, and for your scene. There is a lot yt tuts about optimising Cycles rendering. Official manual might also be helpful.

If you’re new to Blender, I would consider starting out with something other than fluid sims.

If you use Blender every day, and watch a bunch of tutorials, you’re probably still 6 months to a year away from tackling these types of renders.

I think that your issues are probably at the shader level and not at the sim level, but without knowing exactly what you’re after it’s difficult to diagnose.

Can you make the file available?

Seconding @Midphase with .blend file request.

OP, I checked your hardware on Blender open data and it looks like it’s more capable than I previously thought. In that scenario I’d definitely monitor CPU and GPU thermals during rendering. If your hardware is topping at high temperatures (95-100C for CPU) or oscillating that means throttling. And there is not very much you can do about it aside from scene and rendering optimisation.

well Im not NEW new, I’m working with blender for a year, before I was working 1 year C4D studied Maya in academy and played around with Rhino. So I have some experience with this, im not that good at final renderings tho, and smoke sims are a new thing for me and that’s what I want to tackle. Thank you for the support, I will give updates when I resolve the problems I have here now.