Morphing clouds ?

[Tom]

Rob had come up with a cool way to make clouds very realistically tumble in the sky the way real clouds do. My question  is, is it possible to create an animation whereby realistic looking clouds take the shape of something recognizable (like the profile of an animal.. a horse? ) and then tumble back into a wispy shape....

I myself am unaware how the clouds would be able to take the necessary shape but maybe someone else does?

 

Tom

[robcat2075]

As a first gambit, recall this test from several years ago...

 

Those clouds are modeled shapes that emit one layer of sprites on the first frame, which then live for the duration of the shot. The clouds could potentially be any shape.

Since they are sprites one could add a force and turbulence  that slowly blows then out of the sculpted shape.

For getting into the shape, how about another shot with the force blowing in the opposite direction, then reversing the frames so that the sprites appear to arrive at the shape rather than leav it?

Then edit the two renders together.

[Tom]

Very interesting......thank you

How big are the sprites in that render?  They appear to be rather large and shaded...

 

 

[robcat2075]

1 hour ago, Tom said:

Very interesting......thank you

How big are the sprites in that render?  They appear to be rather large and shaded...

 

 

 

there's a zip with a PRJ in this thread

https://forums.hash.com/topic/41565-cloud-fly-thru/?do=findComment&comment=369290

 

A sprite needs to be custom designed for each shot to appropriately represent the light/darkness/shadow direction that matches the lighting in the scene, so the sprite in that PRJ will not necessarily work for another scene.

 

I recall we did a Live Answer Time where we got a force to blow particles away from a shape:

 

[Tom]

Yes, that was a cool particle project. I will have to play with the zipped sprite cloud file I just downloaded.

Thank you

[robcat2075]

Your original question... how to do these morphing clouds in the fashion of my more recent clouds made with noise combiners...  I'll have to think about that more.

[Tom]

Those were very interesting cloud transformations!

 

BTW- Here is  

 

a force blowing some of the sprite clouds away. This approach has possibilities...

[Tom]

Running a test with the Sprites material and the question is, does the patch count effect the "look" of the material emissions?

Here is a picture of two meshes (project attached) and the denser mesh seems to have a smoother looking cloud...

It would seem that the more patches, the "busier" the picture would be but this is not the case.. Can anyone explain this phenomenon?

 

(BTW- the picture is from 30 rendered.)

CloudSpriteNewTests.prj CloudletDisc.tga CloudletDiscDarker2.tga

[robcat2075]

On 5/9/2024 at 10:34 AM, Tom said:

Running a test with the Sprites material and the question is, does the patch count effect the "look" of the material emissions?

 

I have often wondered if particle emission rates are per patch or per group. Your test  project is a good chance to examine this.

First, however, I'll note that the two squares in the Chor are not quite equal. DenseMesh is about 100 cm across while SimpleMesh is about 150cm across then scaled down to 62%. Scaling an object will scale the particles it emits so that may explain why Simple has sharper corners than Dense...

 

If I edit the squares so that both are 100 cm across and both 100% scaled in the chor, they are starting to look much more similar...

 

The emission rate in the Sprite Emitter is set to "1000"...

 

It's possible that is so high that an overload of sprites is masking any difference between the two results. I'm going to scale that value down by adjusting the Emission rate in the Sprite System. This value is always a percentage, not a count.

 Why are there two controls for... the same thing?

It is possible to have more than one "Sprite Emitter" as children of the "Sprite System". For example a fire material might have a flame sprite, a smoke sprite and a spark sprite, each with its peculiar settings for many of the parameters we see in "Sprite Emitter". Having these percentage settings in the "Sprite System" lets us uniformly scale the whole effect without needing to edit each emitter.

 

With the emission rates scaled down to 1% we can observe the sprites being born...

Frame 0:

 

Frame 5

 

Frame 10:

 

Frame 15:

 

Frame 20:

 

Frame 25:

 

Even though DenseMesh has 25 times more patches than SimpleMesh, both seem to be putting out an equal number of particles. This is the opposite of what I expected. I thought the number of particles would increase with the number of patches.

I thought the lumpy result your original PRJ had for SimpleMesh was because it had fewer sprites to blend together, but it was really because they were scaled smaller and perhaps had less overlap among the sprites.

Thanks for inquiring, Tom!

[Tom]

Rob-

Thanks for doing the testing. That is a very informative analysis of how the software emits sprites.

Thanks!