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Steve Green
07-06-2006, 03:54 PM
Hi,

Although this is only using SuperSpray, I've been playing with trying to get a nice water shader without use of any commercial plugins.

http://www.stephendgreen.pwp.blueyonder.co.uk/water_spray.wmv

It uses cubes spinning at high speed (a few frames for a complete spin with some variation - Brandon Davis' Intermedia Case Studie put me on that track), using object motion blur and a little of John Burnetts Motion blur render effect on top to smooth the more obvious stepping.

There is a bit of the basic translucency shader to give a bit of light, and a small sample of water texture face mapped to the cubes. And very bright specular...

It seems to give quite a nice look of foamy spraying water.

It will be interesting to see how it works with different motion and scale.

Cheers

Steve

SoLiTuDe
07-06-2006, 10:03 PM
Looks great Steve, a little fast, but it looks great :thumbsup: Would be interesting to see if it still works with something a bit slower.

Steve Green
07-06-2006, 10:32 PM
Hi,

Thanks, it should be OK - I think the fast rotation is giving the nice blobby feel without the overhead of metaparticles. Slowing down the actual motion of the particles shouldn't affect the look too much (fingers crossed).

I'll try slowing it down, see if it still holds up.

Cheers,

Steve

Steve Green
07-08-2006, 05:20 PM
Not much slower, but more of a waterfall thing going on...

http://www.stephendgreen.pwp.blueyonder.co.uk/waterfall.wmv

Still seems to work, although I'd probably add some geometry to bulk it out, and maybe some atmospherics for the really fine mist.

I need to have a look at some reference footage.

- Steve

BBR-RB
07-09-2006, 11:12 PM
I think it looks really good :)

Out of curiosity, how many particles were required for that to look right?

Steve Green
07-10-2006, 03:13 PM
Hi,

thanks - quite a few :), on the first one it was a thousand or so in the rate setting for Superspray. I just kept upping it until it looked OK. I guess you could get away with less if you had some geometry blocking out some of the more solid areas.

It's a bit of a double-edged sword unfortunately, object motion blur eats up more memory.

Mental Ray motion blur also seems to run out of memory sooner than IMB.

Cheers

Steve

Neejoh
07-11-2006, 09:33 PM
That looks pretty promising Steve, and especially that waterfall looks awesome. Have to find something about making the upper edge less furry, but it sure has potential

Steve Green
07-11-2006, 09:43 PM
Hi,

thanks, yeah I need to get hold of some good nature DVDs for reference.

I guess at the top it would be pretty flat unless there were some rocks to break against, maybe some just some displaced raytraced geometry for a thin curtain of water.

I might give Mental Ray a try for that - I could try the scanline raytracer, but I'm not sure how much quicker MR would be.

Brazil doesn't have 3D motion blur in v1, which rules out using that spinning cube trick for the particles, and VRay has problems with Pflow as well I think.

Cheers

Steve

Neejoh
07-12-2006, 02:22 PM
Vray is working on it in the new release though.
Vray:: Motion blur for PFlow systems (http://www.vray.info/features/vray1.5_preview/#one)

GettyImages.com has some good material btw, check out this (http://creative.gettyimages.com/source/film/FilmPlayer.aspx?clipID=863-5&brandID=6&Type=Clip&QT=1&width=720&height=604) video.
I guess it's pretty important to spawn a lot of small particles on the way to create the dust/steam or whatever that's called. And when you look at the top edge, you're not far off at all!

Steve Green
07-12-2006, 02:36 PM
Yeah, 1.5 seems to have been on the cards forever - hopefully there'll be some news at Siggraph.

I think maybe a duplicate particle system with a short lifespan and smaller particles would work for the edge.

I want to have a look at getting the nice arcs of water on that stock footage. Not sure if the best way is just to ramp the birth up and down, or to use space warps.

I guess it's similar to that Revenge of the Sith lava spray that was posted a while back.


Cheers

Steve

ukdesigner
07-16-2006, 10:26 PM
GR8 effect there, i like experirmenting with the Particles from time to time. Must say that 2nd one makes me wanna go swimming. Sort of thing u want as a screen saver!

Like ive said in another post, theres no real water system in Max which is a shame. Im sure there could be an easy way round it other than having particles seperate from water geometry.

Id like water particles that when it meets the standard geometory, it blends into it and is clever enough to calculate ripples using real time pyshics etc...

I never really look into plugins too often but there must be a suitable water simulator out there someplace?

~So any info on the material u used on them particles plz?

Steve Green
07-17-2006, 09:01 AM
Hi,

thanks - I'm pretty sure there's no 'one size fits all' water solution, that's commercially available. Flowline is maybe the closest I've seen movies of, but I've no idea how it works or what the plans for it are.

The existing ones tend to be geared towards larger scale, like Dreamscape with no separation of fluids, or smaller scale like Glu3D/Realflow which are not really practical for large masses of water. You just have to comp what you need really.

Regarding the material, it's nothing special, just got a bit of a translucency material and a high specular. It's more the object motion blur and 1 frame spin rate on the cubes that is giving the fluffy look.

Cheers

Steve

HeinoEisner
07-17-2006, 09:32 AM
Steve just wondering, you use obejct motion blur, have you tried with image mb ? just to test it ?

anyway i would like to see the difference.


looking great. :)

Steve Green
07-17-2006, 09:39 AM
Hi,

actually I use a little IMB as a render effect on top.

The problem with image motion blur, is that it's not great on extreme rotations (the cubes are spinning 360 degrees a frame), and also it smudges highlights, which is quite a drawback.

However there is a render effect motion blur which John Burnett wrote (you can download it at www.maxplugins.de), which allows IMB to be added on top of Object motion blur, and I just used a tiny amount to blur the grain slightly.

Cheers

Steve

HeinoEisner
07-17-2006, 09:47 AM
ok, was just wondering cause the render time of Obejct motion blur.

thx i'll look into that render effect.

/cheers

H.Eisner

Steve Green
07-17-2006, 09:54 AM
Hi,

yeah it takes longer, but it's liveable with. The main drawback is it uses more memory.

You can use Mental Rays 3D motion blur as well, but that seems to have problems with memory as well if you have a lot of particles.

Cheers

Steve

scorpion007
07-22-2006, 05:34 AM
how complex is your shader? Maybe its not too difficult to write in RSL and have renderman do the water pass. It has very nice motion blur at no performance hit.

BTW, it looks very nice!

Steve Green
07-22-2006, 09:34 AM
Thanks,

it's pretty simple - it justs the translucency shader in the standard material (even though it is designed more for flat objects) and has a bit of a bump map and high specularity. Nothing complex.

Cheers

Steve

BBR-RB
08-01-2006, 09:09 PM
Hey Steve,

Any chance in sharing your file? I've been having a play recreating what you've done, it looks ok, but the material still needs work and your water seems more "fluid" - tho i've only got object motion blur, not image on so far.

Cheers for starting the thread on this :)

Steve Green
08-01-2006, 09:21 PM
Hi,

honestly there's nothing to it - it just uses the translucent shader in a standard material, so the main diffuse is bluey-white, the translucent colour is a dark greenish/blur and it has a high specular (>100).

Do you have the translucent shader on? You have to have it backlit to some extent to get the translucent effect.

If you still have no luck, I'll dig out the file.

Cheers,

Steve

BBR-RB
08-01-2006, 09:31 PM
Hi,

honestly there's nothing to it - it just uses the translucent shader in a standard material, so the main diffuse is bluey-white, the translucent colour is a dark greenish/blur and it has a high specular (>100).

Do you have the translucent shader on? You have to have it backlit to some extent to get the translucent effect.

If you still have no luck, I'll dig out the file.

Cheers,

Steve

Just looking again, that may be the problem - i could only get the translucency (lume) shader by selecting incompatible (then tried a quick render with MR which looked ok but obviously no Object MB) - rendering with scanline was all black with this shader so i bobbed an omni in and it renders ok..... im guessing im not using the translucent shader appropriately?

Steve Green
08-01-2006, 09:35 PM
Hi,

I wasn't using any mental ray-ness, in scanline there is an option where you can select the shader type, Blinn, Metal, Anisotropic etc. there is a translucency shader in that.

It's designed for flat translucency like leaves, but it seems to work OK with particles as well.


So I was just using standard scanline, object motion blur and a standard material with translucency shader turned on. (and a smidge of John Burnett's render effect motion blur which you can get at www.maxplugins.de)

Cheers,

Steve

BBR-RB
08-01-2006, 09:38 PM
Ahhhhhhhh *ding!* - my bad :) I took the translucency to mean another method - will try re-rendering :)

BBR-RB
08-02-2006, 03:58 PM
Getting there slowly - i need to tweak it further though

The main problem at the moment seems to be to do with the motion blur. Here's what i have so far:

http://media.putfile.com/h2o-34

If you pause the avi part way through you can see that the droplets are quite heavily 'streaked' See attachment:

I've tried altering the OMB settings somewhat with no better results? Maybe my gravity is too strong causing them to move to quickly? Any ideas?

Steve Green
08-02-2006, 04:04 PM
Hi,

I normally reduce the default shutter speed from .5 to around .3.

Also with OMB there are 2 settings (I'm not in front of Max at the moment), but if you lower the setting on the left so it is less than the one on the right, it will make the OMB more grainy/noisy. This looks a bit more natural than obvious steps from the samples used, and can get smoothed off by the render effect motion blur.

- Steve

BBR-RB
08-02-2006, 04:15 PM
Hi,

I normally reduce the default shutter speed from .5 to around .3.

Also with OMB there are 2 settings (I'm not in front of Max at the moment), but if you lower the setting on the left so it is less than the one on the right, it will make the OMB more grainy/noisy. This looks a bit more natural than obvious steps from the samples used, and can get smoothed off by the render effect motion blur.

- Steve

Wow, speedy reply! :)

I'm just playing with it now, I agree the grainy look does look better but it still suffers from the streaking. Playing yours back to back with mine, yours looks more like discreet droplets . I've got the plugin that you used, thanks for the pointer. I have to use tiny amount of it tho otherwise it further blurs the streaking.

Just reduced the duration(frames) - im guessing thats what you mean by shutter speed? Certainly seems to help. I'll re-render the anim

Did you animate the speed to get the bursts of water that occurs?

Steve Green
08-02-2006, 04:34 PM
Hi,

I just put a noise controller on the speed value.

You may want to try reducing the gravity, or maybe using a drag warp to slow things down. I think that combined with a smaller shutter speed will help reduced streaking.

Also make sure that your rotation is set 1 frame, to get the blobby look on slower particles.

- Steve

jussing
08-04-2006, 10:24 AM
Great water material, Steve, thanks for sharing! Very inspirational.
Also make sure that your rotation is set 1 frame, to get the blobby look on slower particles.
By that, do you mean that the particles will spin a full 360 in 1 frame? Is this to hide the fact that it is a cube?

Cheers,
- Jonas

Steve Green
08-04-2006, 10:33 AM
Hi,

yep, exactly - it basically makes it look a bit more spherical/blobby.

Cheers

Steve

BBR-RB
08-05-2006, 07:28 PM
Hi Steve,

I've had a play and this is about as good as I've got it:

http://media.putfile.com/h2o-70

Still not as good as yours, but not too bad

If you get chance i'd love to see your origional file :)

Steve Green
08-06-2006, 06:32 PM
Not the exact same one, but close enough.

http://www.stephendgreen.pwp.blueyonder.co.uk/waterjet.max


- Steve

Laserschwert
08-07-2006, 06:53 PM
Hi,

yep, exactly - it basically makes it look a bit more spherical/blobby.

Cheers

Steve

Is there actually a reason why you're not using spheres as particles? You could use a falloff map to make them get more transparent towards the edges. Or maybe just using bump-mapped (or normal-mapped) "facing" particles with a radial gradient as opacity map... it might speed up the whole thing considerably.

But maybe I'm just not seeing the obvious problems with this.

Steve Green
08-07-2006, 11:59 PM
Hi,

they just didn't seem to look as good really. With sphere geometry, it's going to be more polys than cubes, which when using object motion blur is important as it seems more memory hungry than IMB.

As for normal mapped facing particles - I don't think it would give you quite as nice lighting since it will always face the camera, but maybe it would work.

Cheers,

Steve

jussing
08-08-2006, 08:54 AM
A suggestion for cheap(er) object motion blur is to render out something like 200 frames per second without motion blur, and blend the frames in post - then your computer won't succumb to the insane amounts of memory required for object motion blur on thousands of particles.

Then again, with this technique you don't get the short shutter speed effect, but then I guess you can delete all xx0050-xx200 frames after render (which means you throw away 3/4 of your render, which sucks, but the point is it means you can get object motion blur (ish) on a scene that would crash if you tried to render object motion blur in Max)

An idea for improvement would be if anyone knows how to set max to render frame intervals, like 0-50, 200-250, 300-350, etc... (without typing them all in manually, of course)?

Cheers all,
- Jonas

HeinoEisner
08-08-2006, 12:01 PM
you can do that in the render dialog Ussing :]

seperated by a ","

Frames : 5,1,2, 5-50

if thats what your are asking :)

jussing
08-08-2006, 12:07 PM
No, that's exactly the kind of typing I wanted to avoid, since you'd have to type in every second manually. ;)

(without typing them all in manually, of course)?



- Jonas

Steve Green
08-08-2006, 12:11 PM
Maybe just using camera motion blur would be a better option?

- Steve

Laserschwert
08-09-2006, 03:26 PM
A suggestion for cheap(er) object motion blur is to render out something like 200 frames per second without motion blur, and blend the frames in post - then your computer won't succumb to the insane amounts of memory required for object motion blur on thousands of particles.

You don't have to do that in post, since (at least for motion blur) this can be done with the "motion blur" render-effect. It lets you define the number of subframes to be used for the blur, and it can be used in viewport previews as well.

I still hope that MAX9 ist allowing to render on a sub-frame basis (so setting the frame steps in the render-settings to something like 0.5 to get a double framerate clip, without having to mess with the timeline).

jussing
08-09-2006, 03:43 PM
Of course, camera motion blur, even better. :)

- Jonas

jussing
08-09-2006, 03:58 PM
....which can be combined with the slightest image motion blur, and you're flying. :)

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