Water overflow pool

[Terri Brown]

Hi guys,

 

I almost always get the request to create overflow pools in my 3Ds. To be honest I still don't believe I have found the best way to simulate the effect of the relatively still water on the top surface that gains momentum when it tumbles over the side.

The best I've achieved is to map two different diplacement textures onto a 5-sided box (bottom polygon deleted).

I don't have Phoenix or other simulation related plugins...but was considering using Phoenix if it provides an effective solution to this issue.

 

I would greatly appreciate your experienced input.

 

I have attached an image for reference.

 

Thanks a mil guys.

[Chris MacDonald]

I'm making one right now for a project, will let you know how I get on.

[Nicolai Bongard]

This may be something you have allready tried, but the first thing that comes to mind is to create a five sided box (like you have allready done) and make sure it has enough segments, then you could apply a plane uvwmap that is skewed a bit so that is is not completely flat, and if you apply a displacement in that direction it should in theory generate something that looks like long streaks on the sides and "regular" waves on top. Ill try to give it a go and see if it works, it is still early in the morning for me so there may be something wrong with my idea.

 

Edit: Right, so it sortof worked. I am not sure if you can make it work with procedural noises, but with a texture at least you can make it work.

 

 

I created a box with lots of segments and used a displacement modifier on it, after applying a plane UVWmap that i rotated 10 degrees in all directions. In the displacement i used a caustic texture as it was the first one i found that sortof illustrated the waves, but it should work similarly with a not so "steep" gradient / more wavelike texture. You may have to fiddle a bit with the settings, and even move the waterbox a bit up, but the theory works.

Edited April 5, 2017 by nicolaibongard

[Chris MacDonald]

So after a little playing around I came up with a way to achieve it. This of course does depend entirely on how far you want to go with realism.

 

Firstly I wouldn't rely on render-time displacement - It's too RAM intensive and doesn't give you enough control over the effect.

 

Firstly I think it's worth noting there are (to my eyes) three different things going on that we're trying to achieve.

 

1) normal water ripples on the surface of the water

2) smoother/less ripples as the water speeds up towards the edge

3) longer (vertical) ripples as the water cascades down the sides

 

I think they best way to achieve this is by creating a 5 sided box (as you have been doing) and using turbosmooth, subdivide it. If you use the chamfer modifier too you can then control how "sharp" the water turns the corner as it falls. Then the technique splits...

 

If you want a quick fix (as per my image) then just apply a displace modifier with a noise map, and stretch the z coordinate (or compress the x/y). This will give you a basic effect.

 

If you want to take the effect further I would start using edit poly's (or volume selects) on top of the turbosmooth to create a soft selection whereby you can place specific noise individually - this means you can have the pool with plenty of ripples in the middle, but they fade out to the edges, and the "vertical" noise can be kept to just the edges too - leaving the small area of relatively smooth water where it's just flowing over the top.

 

Edited April 5, 2017 by Macker

[Nicolai Bongard]

The testrender allready looks very good Chris! Keep it up! Your method makes more sense than mine i think. It didnt occur to me that you could stretch the procedural noise, but now that you mention it it seems rather obvious! On a side note: Is the gravel from Arroway?

[Terri Brown]

Hi guys,

 

Thanks for the replies. Appreciate the effort you take to help.

 

I've been pursuing a pretty similar method. Have posted a blowup below. Still far from perfect. I added two separate vray mats to it - one for the top (procedural bump only, no displacement), and one for the sides (displacement only - bitmap, no bump). I applied the displacement to the material and not the object as I wanted a much stiller top. I usually always use VrayDisplacement Modifier but not this time. Do you think it's better to use it?

 

Will see if i have a chance later to do a better render.

 

[Terri Brown]

Oh and Chris, please can you explain a bit more by what you mean by:

 

If you want to take the effect further I would start using edit poly's (or volume selects) on top of the turbosmooth to create a soft selection whereby you can place specific noise individually - this means you can have the pool with plenty of ripples in the middle, but they fade out to the edges, and the "vertical" noise can be kept to just the edges too - leaving the small area of relatively smooth water where it's just flowing over the top.

 

What I understand is that you select geometry and add a noise modifier to that selection? Not noise in the material?

[Chris MacDonald]

I usually always use VrayDisplacement Modifier but not this time. Do you think it's better to use it?

 

By use the displacement modifier I meant the max one (called Displace I believe) not the Vray one. Are you familiar with it? You will require a lot of subdivisions on your geometry to see the effect hence the turbosmooth modifier.

 

 

What I understand is that you select geometry and add a noise modifier to that selection? Not noise in the material?

 

Yes, as per my previous comment this is nothing to do with the vray displacement modifier. The techniques described won't work with render-time displacement - these are all set up to work within the viewport for instantaneous feedback. Will try and post an example max file in the morning.

[Terri Brown]

OK cool thanks Chris. This is what I eventually came up with. Still not 100% convinced...will spend some more time tweaking...

 

[Chris MacDonald]

On a side note: Is the gravel from Arroway?

 

Those are from the forest pro presets library.

[Nicolai Bongard]

Those are from the forest pro presets library.

 

Cool, i guess i have to update forest pack again if there are lots of new presets. Thanks!

[Davedraughtsman]

Hi Chris!

What do you mean by "stretch the z coordinate (or compress the x/y)"

Thanks!

On 4/5/2017 at 9:58 AM, Chris MacDonald said:

So after a little playing around I came up with a way to achieve it. This of course does depend entirely on how far you want to go with realism.

 

Firstly I wouldn't rely on render-time displacement - It's too RAM intensive and doesn't give you enough control over the effect.

 

Firstly I think it's worth noting there are (to my eyes) three different things going on that we're trying to achieve.

 

1) normal water ripples on the surface of the water

2) smoother/less ripples as the water speeds up towards the edge

3) longer (vertical) ripples as the water cascades down the sides

 

I think they best way to achieve this is by creating a 5 sided box (as you have been doing) and using turbosmooth, subdivide it. If you use the chamfer modifier too you can then control how "sharp" the water turns the corner as it falls. Then the technique splits...

 

If you want a quick fix (as per my image) then just apply a displace modifier with a noise map, and stretch the z coordinate (or compress the x/y). This will give you a basic effect.

 

If you want to take the effect further I would start using edit poly's (or volume selects) on top of the turbosmooth to create a soft selection whereby you can place specific noise individually - this means you can have the pool with plenty of ripples in the middle, but they fade out to the edges, and the "vertical" noise can be kept to just the edges too - leaving the small area of relatively smooth water where it's just flowing over the top.