Howdy Folks,
I’m tryin to get a nice foggy smoke sim coming out of this crate, and I’m happy with all of it, except… I can see the smoke through the crate for some reason?
I cannot for the life of me figure out why.
I’m working on getting some screen shots, but while I’m at it, anyone got any ideas?
I am using Eevee, and the issue only happens in Eevee, in cycles its fine.
The crate is already a smoke collision object, that’s why the smoke is staying in that weird shape inside it… It fills up and overflows… But I can see it filling up through the sides.
Is there a second smoke collision setting somewhere for rendering or visuals? Not just the physics?
Well, I think the problem is solved.
Blender Eevee render is extremely (game-related) fast.
But at a cost, it does everything simply. Light, shadow, and volumetric rendering.
You can turn things on, tweak options, but then Eevee gets slower.
For smoke, this is the same. To avoid heavy collision calculations it doesn’t do it at all.
Maybe in newer versions. If you have a smoke sim in a sphere volume, Cycles draws a sphere.
But Eevee uses a box with the dimensions of a sphere.
In this example, working with Eevee, you can see the cube forms of fog.
Maybe switch over an image plane with fog, blending into the rendered image. I do that with smoke.
I appreciate your response again Pete, but I’m afraid this isn’t the solution either.
I have done a lot of rendering smoke and fog in eevee, and while you’re correct about it being limited to square shapes, this exists fully inside the domain, and, you should be able to see in the image, is not using the full domain. The fog coming out of the top is not in a square shape. The shape is square inside the collision object because the collision object is square.
The smoke flows out of that square and spills out onto the floor. But I can see it through the Object.
This issue is not about the shape of the smoke.
The issue is about seeing the smoke through a solid object.
I’ll try adding some more screen shots to show what I mean.
For another example, I’ve moved the smoke object above the box, and re-baked again. Here I am looking up from below, through the floor, and crate, and still the smoke is visible.
I started with an image of smoke on a plane. It turns out, that can’t fill an object, and overflow out of it. This can. I’m trying to improve my render and learn smoke sims.
I’m trying to understand why I can see smoke through a solid object. The smoke isn’t coming through it. It’s just visible through it.
Could it be related to the emissive volume settings I am using?
It’s the eevee simplicity!
And in Cycles the object need to be collision? I have to look that up.
So you are telling me any smoke or fluid rendered in eevee is visible through any solid mesh? If I make an explosion, I can’t obscure part of it behind a building? If I make a cup of coffee, the coffee will be visible through the cup? I find that hard to believe. It doesn’t happen in matcap mode…
I’m not sure what you mean. Any smoke simulation object, regardless of render engine will need to be set as collision if you want smoke to interact(collide) with it.
when in matcab, a eevee version is used. So this is interesting…
I know - I’m tellin ya… something is up!
this help?
I’ve looked into an old project of mine. Which I abandoned, because of Eevee problems.
When I run the animation it follows the collision object, but it render in a completely different scale and location … I still think it’s still too complex for Eevee to handle.
Maybe as a test. Just start with a new basic low poly object. An smoke emitter and a box as as collision. and a lid object also collision.
That’s a solid tutorial, but all information I’ve already got, so unfortunately, no help for this issue. I will be using that tutorial resource in the future though!
I think Making a new scene is pretty much the only step left. Gonna make a few test things and see what I can come up with. If I can make smoke that’s not visible through objects… then there’s gotta be… something, some way… . I’ll update after some experimenting.
Yes, that is what I try to say.
Start a small simple controllable test.
That is why I did, but I abandon it.
Let me hear about your findings!
I seem to have similar issues when I make other similar setups, It seems that the smoke just… clips through. The inly thing I can find that suggests a solution is cranking the Resolution Divisions up wayyyyyy high, which would probably take longer than just using cycles to render.
Smoke can be hidden behind an object, but, when it gets really close to it, it seem to just… show through.
I haven’t tested a crazy high number of Divisions, cause that’s just… too time consuming. Maybe If i were working for ILM. =D
Just Eevee weirdness. It is a good render, but when high calculations are needed, then short cuts are taken.
Eevee render only what can be seen through the view port. The rest is removed from the calculations.
So maybe? The back face of the cube are gone (you don’t see then, so eevee discards them). And the smoke travels further. It’s wierd.
But to be sure! This dark textured cube is marks as a collision object form smoke as I displayer earlier?
Yes, I am very sure that the cube is a collision object. I even proved it in the images above, in a previous reply.
It seems to be a clipping issue in Eevee. The internet suggests that a super high division can mitigate it.
Instead, I solved the problem with some invisible walls, and camera angles that never let the fog move behind a wall.
Looks very good. Cool box, frozen ‘stuff’ in it!
