3
$\begingroup$

I would like to model a so-called stormwater overflow (used within a sewage system) which is a concrete chamber in which the water level is rising during a storm inflow until the crest of an overflow weir is reached. Then, the water forms a small waterfall. I would like to have some waves on the water surface and one should see the water "falling down" at the overflow. It should look like this:

enter image description here

The use of the FluidSimulator of course would be straightforward, but it did not work properly in some first tests and was also very time-consuming. To complicate it a bit, the weir should be movable, going down while the water is overflowing, so there will be changing geometry.

So I ask whether there would be some way to "fake" the water. Ocean modifier plus some additional modifiers?

Greetings from Germany, Tschöbbel

$\endgroup$
  • 1
    $\begingroup$ Welcome to Blender.SE. This seems, as you already pointed out, a job for the fluid simulator. If you don't want to use it, try to describe which kind of effects you may be allowed to give up. Also a quick scketch of the animation would be useful to clealy understand the situation. $\endgroup$ – Carlo Jan 30 '18 at 20:53
7
$\begingroup$

Final:

final

You can fake it pretty easily with creative UV Mapping and animating Texture location. I've used Noise Texture for it as a Bump for Principled BSDF.

Let's break it down.

Mesh:

It's simple Plane with one edge Beveled. Nothing to add here.

Mesh

Material:

We need to add material first, it will be easier during UV Mapping.

Again, nothing to fancy here.

material

Animating.

X value in Mapping node will be animated - in this example keyframes are on frame 1 with value 0 and on frame 60 with value 1. In your case axis could be different, also bigger difference between values will give faster animation.

After adding keyframes you should go to Dope Sheet editor, select both frames from X axis and choose Key > Interpolation Mode > Linear.

UV Mapping:

Go to Edit Mode, Select All and U > Unwrap.

uv_1

Now changing X axis value in Mapping node should give as something like this (I'm using Node Wrangler to be able to see Color Ramp node output):

uv_2

Go back to UV Image Editor, select faces where water should be flowing faster, enable Proportional Editing and scale them down along X axis as much as you want.

uv_3

Final thoughts:

This is basic overview for the water flow. You should also add some Particle system for the splashing water and maybe some foam texture. I think those should be another questions otherwise this one could become to big/tutorial like answer. Or just search trough the web, there are plenty tutorials about this.

| improve this answer | |
$\endgroup$
  • $\begingroup$ Wow! This is exactly the effect I would li $\endgroup$ – Tschöbbel Jan 31 '18 at 12:49
  • $\begingroup$ Sorry, I fight with some issues of my smartphone, maybe something was double. Wow! Dear Luke, this is exactly the effect I would like to obtain. Thank you very much for your very detailed answer! I will try that out within the next days. - Greetings, Tschöbbel $\endgroup$ – Tschöbbel Jan 31 '18 at 12:52
  • $\begingroup$ @Tschöbbel I will also try to experiment with foam texture and particles and maybe add this as a simple overview with blend file included. $\endgroup$ – cgslav Jan 31 '18 at 12:54
  • $\begingroup$ I just tried your proposal and I was successful at the first try! Thanks again for your good description. $\endgroup$ – Tschöbbel Jan 31 '18 at 20:03
  • $\begingroup$ After browsing through some other questions relating to "water" in this forum, I got the idea to use a procedural texture as displacement texture (UV coordinates, normal) for a highpoly water surface using the Displace modifier in order to get real geometry (no high waves, just a bit). With a simple Voronoi texture, this works well. Is there some way to animate the textures used by a Displace modifier? One idea is perhaps to make an animated bitmap as a movie? Or is there a possibility to use the output of your bump texture with animated coordinates as continuously varying displacement map? $\endgroup$ – Tschöbbel Jan 31 '18 at 20:13

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.