bBox fog density

[darioOrtisi]

How do I get it to control the density in an Axis with fCurve?

Thanks

[darioOrtisi]

There is some reference that i will look at?

Thanks

[morten.bojsen-hansen]

You can get the bounding box of a fog density volume using the volume_bounds node.

[darioOrtisi]

Thank you @morten.bojsen-hansen is clear i got into volume_bound but i will  like to control the density on axis. Like a ramp on axis. I didn't explain well maybe.

thanks

[darioOrtisi]

Hi. I have tried many times without success. I find this in houdini, no able to get the same result. 
https://www.youtube.com/watch?v=6kjvYZ29_ug&list=PLvCneS4CeezdnLg8zjqFxKsFAaA4rW7Us&index=24

[morten.bojsen-hansen]

@darioOrtisi This is an almost two hour long video so I wasn't able to quickly understand which part you were having trouble with.

If you want to control density you can just multiply it by a scalar. If you've got the volume bounds you can interpolate this scalar from e.g. y_min to y_max. For example you can linearly interpolate from 0 to 1 from y_min to y_max so the density is zero at y_min and maximum at y_max. You can even get more control using an fcurve, if you want.

[darioOrtisi]

Thank you @morten.bojsen-hansen My bad, sorry.

Yes i need to interpolate min max, so i want the max Y is controlled (like fade off to up) Like a fog on fluid Effects.

Anyway  i cannot able to get what i want. 

This is what i get, so nothing. I can remap fog from border to center, simple as is, but not from a specific axis. 

[morten.bojsen-hansen]

I am sorry but it is still not very clear what exact result you want. The screenshot of the graph is obviously incomplete so it doesn't help me much in understanding either, unfortunately. It would help immensely if you could clearly and concisely state exactly what you want to achieve.

[darioOrtisi]

Hi @morten.bojsen-hansen 

I'm ashamed to be able to explain better what I would like to create. I am very sorry.
If you look at the previous image with the fluid effects bbox and its curve you will see that I can control the fog density based on the direction of the axis. So as you go up the density decreases. IN bifrost, yes, the graph is not complete because I can't move forward. I can't understand what I should do.
In the video I showed you what I want to achieve is more density at the base and less density towards the top.

In the video he use the turbulence to create some sort of foggy turbulence on the top. So more density on the bottom and as it gets closer to the top of the box, he get less density. 

[darioOrtisi]

I've recorded a video. I can decrese the total density not only like a falloff on Y axis

[morten.bojsen-hansen · Accepted solution]

Try this compound.

[darioOrtisi]

Thank you very much @morten.bojsen-hansen. It is it and works perfect