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Leprechaun
08-21-2005, 04:26 PM
Ok some im just fooling around with Hypervoxels and im trying to make it look like water is flowing down steps. Does anyone know why there is a gap in the water between the first step and the second step? Also if anyone knows how to or any good tutorials on how to make water can u show me?
thanks

alvin_cgi
08-22-2005, 06:19 AM
desktopimages have a training dvd called "Understanding HyperVoxels: Volumetric Concepts in LightWave 3D", looks like something you are looking for. :D

http://www.desktopimages.com/Hypervoxels2.shtml

MonroePoteet
08-22-2005, 02:33 PM
Particles and HV may not be the best solution here. To get a sheet of water running down the stairs, Cloth FX may work better.

Regarding the gap, in my experiments, the gap can be eliminated by changing the Collision object to use Object-Advanced as the collision detection mode. It looks like the 90-degree transition from horizontal to vertical on the steps confuses the normal object collision detection, causing them to be "sucked" into the fall.

Using Cloth_FX will work better for this. For a cloth solution, here's a really rough tutorial and attached scene file:

1) In Modeler make a subpatched sheet of material with a fairly high number of divisions
2) In Layout, load the sheet above the stairs and angle the sheet as if it's falling water. Move the sheet in the direction down the stairs during the animation.
3) Apply Cloth_FX to the sheet. Make Weight 1000, Viscosity of 1.0, and Substructure of 10.0. All other parameters should be 0.0.
4) In the Cloth_FX=>etc panel, set the Y gravity value to -9.8
5) Set the Stairs as a Collision object. Set the collision type to "Object-Advanced", the Fix/Bounce percentage to 150%, the Fix power to 1.0 and the Roughness to 10%.

When you do the Calculate in the Dynamics tab, the gravity will cause your cloth sheet to fall and hit the stairs. The motion in the direction down the stairs will cause it to flow. The fix/bounce percentage and fix power will make the water flow down the stairs.

In terms of surface for the sheet, pure water is 100% transparent. The only reason you see it at all is because of reflections or refraction. The Edge_Transparency shader is invaluable for making glass, water, etc.

See the attached scene file, etc. You'll probably have to play with the various parameters to get what you want. Hope it helps!

mTp

richdj
08-22-2005, 02:55 PM
desktopimages have a training dvd called "Understanding HyperVoxels: Volumetric Concepts in LightWave 3D", looks like something you are looking for. :D

http://www.desktopimages.com/Hypervoxels2.shtml

The desktopimages DVD's are excellent and well worth the money...

Particles and HV may not be the best solution here. To get a sheet of water running down the stairs, Cloth FX may work better.

Regarding the gap, in my experiments, the gap can be eliminated by changing the Collision object to use Object-Advanced as the collision detection mode. It looks like the 90-degree transition from horizontal to vertical on the steps confuses the normal object collision detection, causing them to be "sucked" into the fall.

Using Cloth_FX will work better for this. For a cloth solution, here's a really rough tutorial and attached scene file:

1) In Modeler make a subpatched sheet of material with a fairly high number of divisions
2) In Layout, load the sheet above the stairs and angle the sheet as if it's falling water. Move the sheet in the direction down the stairs during the animation.
3) Apply Cloth_FX to the sheet. Make Weight 1000, Viscosity of 1.0, and Substructure of 10.0. All other parameters should be 0.0.
4) In the Cloth_FX=>etc panel, set the Y gravity value to -9.8
5) Set the Stairs as a Collision object. Set the collision type to "Object-Advanced", the Fix/Bounce percentage to 150%, the Fix power to 1.0 and the Roughness to 10%.

When you do the Calculate in the Dynamics tab, the gravity will cause your cloth sheet to fall and hit the stairs. The motion in the direction down the stairs will cause it to flow. The fix/bounce percentage and fix power will make the water flow down the stairs.

In terms of surface for the sheet, pure water is 100% transparent. The only reason you see it at all is because of reflections or refraction. The Edge_Transparency shader is invaluable for making glass, water, etc.

See the attached scene file, etc. You'll probably have to play with the various parameters to get what you want. Hope it helps!

mTp

Man this is escellent, cheers for the scene, had a quick look and rendered it and it's great, and very quick..... Thanks...

Rich

Leprechaun
08-22-2005, 03:38 PM
thanks for the help. As for the dvd's. ive seena few on how to create water using particles and HV's, but i wanted to see if i could find something online before having to buy something. thanks monroe. i switched the object type and now it flows more smoothly.As for the cloth_fx, i havnt tried it yet but i will be shorty. thanks again

Leprechaun
08-22-2005, 03:58 PM
ok i was trying the cloth thing. i downloaded ur scene and i got all teh objects and the movement and the cloth settings are there but nothing happens. The cloth just sort of floates above the stairs in its normal state. And the settings are all correct.

MonroePoteet
08-22-2005, 05:34 PM
Be sure to go to they Dynamics tab in the object Properties and press "Calculate". Otherwise, gravity never effects the object, and it just floats.

mTp

Leprechaun
08-22-2005, 06:09 PM
yup that worked lol. thanks. i dunno if im gonna do it , but do you know how to get a splash effect for when the water falls onto the steps?

MonroePoteet
08-22-2005, 07:51 PM
I'm not sure what kind of "splash" you're looking for. If you want globs of water heading off in various directions, that's a good application of FX_Linker.

On the other hand, if you want more droplets around the various places that the water sheet hits the stairs, probably the easiest way is to clone the sheet, reduce its Viscosity setting in the Cloth effects (makes it "wilder" in collisions), and then put something like a little inverted Crust clip map on it.

I just tried it, and it seems to work:

1) Clone the water sheet object
2) Change it's Cloth_FX Viscosity to 0.2
3) Add a Crust Clipmap to the object:

Object Properties
Render Tab
Clip-Map button
Crust procedural texture
Size of (0.1,0.1,0.1)
Coverage of 0.50
Moving pretty rapidly in the Y direction with an Envelope
Invert the Procedural layer, so it's mostly transparent

The original hit on the stairs is a little too constrained, but otherwise the lower viscosity, clip-mapped clone really adds a dimension to the cascading water. Definitely increases rendering time, though, due to multiple levels of calculated refraction from the multiple water objects.

mTp

Liberator
08-23-2005, 05:22 AM
You might want to take a look at the Water FX CD from Tutor FX (http://www.tutorfx.com/) . It's only \$19.95

GregMalick
08-23-2005, 10:07 AM
This sheet idea is a great technique. :thumbsup:
If we could only reduce the rendertimes to something reasonable....

MonroePoteet
08-23-2005, 02:15 PM
"To create is difficult, to criticize is easy."

For my part, I'm astounded at what Lightwave can do. I don't consider the render times for this scene to be unreasonable considering what's involved with raytraced refraction, raytraced shadows, reflection maps, subpatch calculation, cloth simulation, texture calculations, etc. etc. etc..

mTp

GregMalick
08-23-2005, 04:18 PM
This sheet idea is a great technique. :thumbsup:
If we could only reduce the rendertimes to something reasonable....
mTp - no criticism of your technique was ever intended by the above.

Leprechaun
08-23-2005, 04:30 PM
yea the cloth_fx works great for this. Im considering getting the water_fx dvd and maybe the pyro_fx one aswell. Anyone know if either of them are worth getting?

GregMalick
08-23-2005, 07:54 PM
I have the water_fx and it's pretty good. Uses HV sprites instead of cloth so it looks like a white water rush. Take a look at the video on their site.

I have no idea about the pyro_fx tut.

GregMalick
08-23-2005, 07:59 PM
opps double post