I wandered lonely as a...

[GeorgeP]

Hi All

Apologies if I'm posting in the wrong section, but I don't like asking questions in Tips & Tricks, since it says it's for errr... well, tips and tricks.

Anyway. With the recent arrival of VRay Sun + Sky, I've been wondering about volumetric clouds. I do a lot of outdoor scenes and I'm getting sick to death of the few decent sky images that I have. Even the big ones aren't high enough res for spherical environments - not for stills for print, anyway.

After googling volumetric clouds, I found this on cgchannel:

http://www.cgchannel.com/gallery/vie...sp?imgID=11377

apparently the clouds are volumetric created in Cinema4D! Pretty impressive.

Does anyone have any advice on how to do this in Max?

Are the built-in tools any good or do I need a plugin? I can't find a demo of pyrocluster or afterburn.

Failing that, does Aura do decent clouds? Is its arrival imminent?

The stuff I see in this forum has got to be the best in the world - I'd love to hear how you guys do decent skies...

Thanks all

[instinct]

For skies as seen from the floor Dreamscape and For flythrough Afterburn.
i posted 2 5min setups here : http://www.chaosgroup.com/forum/phpB...ght=dreamscape
That's dreamscape

Regards,
Thorsten

[joconnell]

Afterburn and pyrocluster are for doing clouds, aura isn't really. The main difference is that AB and pyro use particles to position spheres and then use a volume shader to put a puffy ball of smoke inside that. You're effectively using a noise shader inside that sphere to control the transparency of the smoke effect so you can control stuff like the breakup of the edge, the size of the noise along the edge and the transparency. Afterburn and pyro both get really nice results visually, especially for bigger looking smoke and fire such as rocket trails, volcanos and so on. Where they fall down though is in their movement. Since you're using particles to drive the movement of the smoke, you may find it quite hard to get realistic billowing and churning where the particles are curling around each other (think of a mushroom cloud for example)

Aura and fumeFX on the other hand aren't great for doing huge clouds since their sophistication and accuracy may be overkill for getting the big cotton ball type look of afterburn. Where they beat the other two is in their movement - they use fluid dynamics to give you incredibly realistic movement where they react correctly to other objects in a scene and pick up wind resistance so if you want a proper fire effect or even a small bit of smoke curling correctly, then you'll need aura or fume.

In your case I'd say afterburn or dreamscape are both good bets - DS has a lot to offer in terms of landscapes such as nice mountain and sea objects - It also has a procedural sky with some of the volumetric cloud effects from afterburn. You can get the ab and ds demos on http://www.turbosquid.com/FullPrevie....cfm/ID/197839


http://www.turbosquid.com/FullPrevie....cfm/ID/197839

[studioDIM]

I should also suggest you go look for the preview of Terragen 2.
The tech preview will be out in a couple of weeks, and the new images added are nothing but stunning. Best digital clouds i have ever seen.
It might be worth a shot to create some hdri backdrop, or to cut a flythrough sequence into the standard max animation (purely with video editing, of course).

http://planetside.co.uk/terragen/tg2/tech_preview.shtml

Remember the gallery!

Lele

[GeorgeP]

Thanks for your comments, guys.

instinct and joconnell:

I think I might be tempted to go with DreamScape, although the clouds still aren't as realistic as I'd like. There are no demo versions for Max 9, and annoyingly, the Max 8 demos for DS and AB reset all my settings when Max auto-saves!

I think for now I'll carry on with what I've been doing, which is to have my clouds bitmap mapped to screen env for the Max BG, and then mapped spherically for VRay reflections. Not a great solution, but it's kept me going so far.

Lele:

I had already seen the Terragen 2 preview, and yes, it looks pretty cool. I currently have Vue D'Esprit which I use from time to time, but it's tedious to create environments in one package and then re-create lighting etc. in Max. I was hoping for an all-in-one solution, really. I'll keep my eye on the planetside website, though...

-------------

By the way, what got me interested in volumetric clouds was the image I linked to in the cgchannel forum:

http://www.cgchannel.com/gallery/vie...sp?imgID=11377

The artist said

"It is a relatively simple 3d composite rendered in c4d with radiosity and volumetric clouds, i kept it simple as..."

well, ain't you a little fibber! I found this on Google images:

http://images.google.co.uk/imgres?im...005-37,GGLG:en

What a coincidence! The "volumetric" clouds created in Cinema4D have come out exactly the same as those in this photograph! Weird!

Oh, I'm only kidding. I've told the odd fib or two myself before now.

Better cancel my order for Cinema4D, though...

[Paul Oblomov]

Afterburn is best choice for you. Forget about pyrocluster, as it doesn't work correctly with VRay.
I'm not sure about DreamScape, as it's a complex package... But, it creates stunning clouds too.
And yes - there's still no max9 versions

[studioDIM]

ah, i've seen those clouds now...
I *think* he's cheating by using a backdrop, and boasting uselessly (see the 4.5/10 rating) about an animation.
If there is something with very little shortcuts, number-crunching-wise it's volumes.
To get to the detail he has in those clouds, well, it would take some time to work on, and a LONG time to render.
No bull****ing me about quick rendertimes there.
My 5c

Lele

[glyph]

here's a link to a tut on making procedural 2d clouds

http://www.lemiere.com/tutorials/tut..._cloudmat.html

the results are nice and subtle

[dapeter]

Well if you have Vue D'esprit why not just upgrade to Vue 6 Infinite? I got the pre-release buggy version, but the new spectral atmospheres are incredible. If you upgrade to the Infinite version, you can just render out 360 degree HDR pano's of the sky and use that as an environment in Max. I just ended up figuring for the price you get the functionality of Dreamscape with the skies, a bunch of trees you can export to Max and use if you have to, and the ability to create landscapes and matte paintings for compositing.

Or you could give it a few weeks and wait for the e-on Ozone 3 to come out and see what that looks like.

[priad]

Terragen2 seems amazing in term of quality!!

[GeorgeP]

Thanks for your comments everyone, much appreciated. I think I'll hold fire on the volumetric stuff until I really need it...

dapeter: I think I will look at upgrading my Vue D'Esprit. The xStream version works inside of Max - pretty exciting, will definitely investigate that further!

Meanwhile, I've been looking for decent sky/cloud images for background environments which got me thinking (uh-oh). I did a quick test tonight:

I took a grid image I often use when I'm texturing*:



and placed it in the environment of a new scene, spherically mapped. Then I rendered the scene at 800x600, with a 35mm standard camera. Here's the image I got:



by my estimate, I'm seeing 61 horizontal pixels of the original image stretched to 800 wide. That's 15.25%. To match my rendered output pixel-to-pixel at this resolution, I'd need a background image of

(800/15.25)*100 = 5246 pixels wide

If I were to create a high-resolution image (which is what I do most of in my day job) at, say 4000 pixels wide, and I wanted the background image to match pixel-to-pixel, I would need a background image of:

(4000/15.25)*100 = 25397 pixels wide!

Is this right or am I missing something? No wonder my backgrounds suck so much when I use spherically mapped bitmaps as the environment!

Am I really seeing so little of the world with a 35m lens? I must be doing something wrong here - can someone put me right? I know very little about cameras/lenses/the world/anything

EDIT: oops, of course that's right - I'm slow, but I get there in the end!
35mm camera = 54.43deg FOV.
54.43/360 = 0.1512 ie 15.12%

bummer...

*if any you AutoCAD guys are interested, I wrote a Lisp routine to generate these grids - you put in the rows/cols and it creates the grid. You can then plot to a PDF and open it in PS. I still use grids like this even with the advent of UVW unwrappers .

[priad]

I'm interested as a max user!

[Sawyer]

Do you use this same formula for your building textures?

[studioDIM]

That's of course very true, but that's why it's nice to have screen mapping
You can safely (in most cases) use a lower res BG as reflection, and a higher res image as screen (or plane, depending on the shot requirements) projection.
The two needs to be just barely resembling each other in tones, especially for clouds/skies, so with a bit of PS or HDRShop it should be easy to match the tones of the visible background to the reflection one.
If it's high-res it's also *probably* a still, so you can do easier math t work out what you need the BG at.

Of course, if you need a 360 pano at 4k res, you'll have to get creative

Lele

[GeorgeP]

Lele: Yeah, that's what I have been doing (see my earlier post), I just didn't realise how little of the BG I was seeing with spherical mapping. Maybe that's why I get splotchy images from HDRI too?

I feel some more tests coming on...

...you'll have to get creative

What a scarey thought!...

Sawyer: sorry, I don't understand your question!? I never applied any formula before, but for object mapping this wouldn't apply anyway...

Laurent:I wasn't trying to alienate anybody, but I wrote the grid program in AutoLisp, AFIK it will only work inside of AutoCAD

I've been trying some other techniques today, in particular mapping individual clouds onto planes to use as billboards against a gradient environment. The hard part is getting the cloud images. Does anyone have any tips for extracting these from photos in PS? I've had some success with desaturating the image and then copying the greyscale to a new Alpha channel and selecting that from a plain white layer, but the edges tend to suck a bit...

This is starting to get complicated...