Cloud FX for Rolling, Evolving Cloud

[dszs]

Try messing around with flow rate with tandem to flow? It seems that they affect each other somehow?

[shiv_d]

I have already done that(mess around with flow rate).

I think the issue is the aaflow noise(high band noise). Increasing the volume samples decreases the noise to some extent.

Have to render it out to see if that alleviates the problem.

[shiv_d]

Hi,

 

So, I'm having a rendering issue. My render window MPlay goes completely black and it says No Image at the top left. I have restarted Houdinia nd my PC, both but to no avail.

 

Any ideas? Thank You.

[Guest tar]

have you placed a camera in the scene?

 

It's really really hard with a test file- try creating a separate test setup so we can all check your setting please. Alternatively most issues can be resolved by running a simple test outside your current production file.

[shiv_d]

Yes, I have a camera in the scene. I'll try to prepare a test setup file.

[shiv_d]

So, I have more or less addressed the noise.

I am doing a smoke sim using the cloud volume as a source for emission.

I need to affect them with a custom turbulence field that is in the shape of my cloud volume source. Is there a way to do that?

I am guessing using the Sop Scalar Field as a mask from the cloud source volume would work the best.

Let me know your thoughts.

[exu]

Hi Shiv,
I did years ago, a setup for rolling clouds, before the "cloud rig " in the shelf, so my solution was using a normal attr of poly spheres to create a volume field, using "volume from attribute" and apply into a smoke sim, no gravity, buoyancy etc,   just sop field and gas calculate node attached to velocities slot on solver, it may help a lot if you using time blend to interpolate frames, since simulations involves sub frames.

I hope it help you.

 

So, I have more or less addressed the noise.

I am doing a smoke sim using the cloud volume as a source for emission.

I need to affect them with a custom turbulence field that is in the shape of my cloud volume source. Is there a way to do that?

I am guessing using the Sop Scalar Field as a mask from the cloud source volume would work the best.

Let me know your thoughts.

[shiv_d]

Thanks for the prompt reply, I appreciate it!

Do you have a scene file you can share?

[exu]

Hi Shiv
i didn't have it, i lost my old HD,   
but i did a simple exemple for you... this is the basic concept, to get a movement
but you can play adding more rotations on copy, add some noise using rest, vel, and density fields with vop volume or cvex ...

 

I hope it help.

i forgot

in minute 3:00 you can see the result tahat you can get with this trick...   

 
 

 

Thanks for the prompt reply, I appreciate it!

Do you have a scene file you can share?

 

rolling_cloud_simple.hip

Edited September 27, 2014 by exu

[shiv_d]

Thanks a lot, I really appreciate it!

[Whatsinaname]

I'm also working on some clouds, but my hopes are still high I can get away with the standard CloudFX setup (Only CloudFX, not the Sky Rig in H13, I think it doesn't give you the right amount of control and needs some improvements).

 

After getting some nice clouds with about the looks I'm after, I was wondering which parameters animate in order to get some motion in there. I tried Animating Time in the Cloud Noise's Advection Tab, but it didn't seem to have any effect at all or it was that subtle I didn't see it.

 

Any suggestions for other parameters to animate?

[shiv_d]

So, I am stuck on another issue. That is, the cloud tool source geo only works when a few units away from the origin. If I translate the source geo way out in world space then it doesn't work.

 

Do you guys think this is an OpenGL refresh issue?

 

Please advise. Thank you.

 

Regards,

Shiv

Edited October 13, 2014 by shiv_d

[shiv_d]

Hello Everyone,

 

My CVEX multi-fractal based cloud rendering in PBR mode takes a very long time and sometimes doesn't render at all. My camera is going through the volume so it is right next to it.

 

I would appreciate any suggestions for optimizations.

 

Thank You.

 

Regards,

Shiv

Edited October 21, 2014 by shiv_d

[Whatsinaname]

Hi Shiv,

 

I'm having the exact same problem as you do, also with a CVEX Sky system and an animated camera travelling through it. I found Pixel Samples to be crucial regarding rendering times and noise, whereas Noise Level seemed neglectable and didn't have a big influence on the final volume rendering after all. I made a series of tests in order to find an optimal balance between noise, quality and acceptable rendering times so I got away with 5/5 and 0.8 for Volume Quality. I also checked in Nuke what level of grain is working in the scene because in the end there will be film grain added on top. However, depending on your setup this might be completely different in your case.

Still, I'm also looking into ways to further optimize that or if there is any special trick or best practice I'm still missing. Did you already find out anything that helped in your situation?

[shiv_d]

I found increasing volume step size also helps reduce render times, but do do within reason.

[shiv_d]

I think part of the problem is also that the cloud volume is right next to the camera further increasing render times.