Let's Build the RPG! - 58 - Unreal Engine 5 Niagara Fluids 2D Interactive Water

[@ManaIndieDev]

As for the water level dropping, if you go to the parent material of the 2D water, there is a comment called "Height". The red channel of the TextureSample is being used for the WorldPositionOffset, so if you lower it (for example by dividing the output), you'll get less "sticky" water that doesn't drop as much.

[@simondelguste]

This is so interesting, and I feel like I learn a lot with this channel ! Thank you so much for your work !!

[@R0w4nH0pk1ns]

I think i disagree on the cast vs interface take. Interfaces are generally better than casting 99% of the time because casting creates a hard reference. So whenever an actor is loaded into memory, everything it casts to is also loaded into memory. This can cause a lot of issues as you expand your game. Also i dont think you needed to run the check if the hit object implements the interface here. If the interface isnt implemented nothing will happen and itll just act the same as your false branch anyway. If you were using an output from the interface function it would be a good idea to keep the check to avoid null references though.

[@SneakyKittyGameDev]

Correct. In C++ it doesnt really matter as it treats it differently than BP does. This is a big thing with using TSubclassOf instead of having a lazy pointer to the object and loading/unloading it as needed!

[@NikomaGrob]

So weird, I can get the whole ripple effect to work without any interface functions needed, just put collider tag on the actor, but what I CANT get to work is having my fireball or any abilities at all for that matter (also tried a manual linetrace into the water and put that on a timer and many other tests) create ripples in the water. I tried every type of trace (sphere, box, lines every direction, different lengths, i added the collider tag to everything as well, just doesn't change a thing) I also see the mesh of the BP dynamic Force component fly around the water when I test, I also debug if it is hitting water physical material, which it is, I also tried setting the strength of the FluidForceDynamic higher, I also played with radius on the sphere, also tried directly attaching the BP Dynamic Force component to the projectiles I am shooting (attach actor to actor). No matter what I try, the projectiles or any other components/actors in the water OTHER then myself won't create ripples. What am I doing wrong, does anyone have a little suggestion or tip?

[@stijnhernalsteen8209]

By unhooking the world position offset in the material to fix the water level problem, you also got rid of the WPO of the actual ripples. Now you can still see the effect because the NS also calculates a normal map for the ripples, but some fidelity is lost. I think the water level issue traces back all the way to the fluid simulation, the render target never fully returns to black, its original state. Maybe there is some way to modify the NS to do that, or wait for a fix from Epic.

[@nickprice6644]

The ripples are not occurring when my player steps into the water. First I haven’t done sessions 20 / 21 or session 57, but have done the steps suggested in session 57 relating to the settings on SM_WaterPlane. The Event Footstep Niagara Water from the interface is not getting invoked (I’ve set a break point on it). In the footstep line trace I’ve logged the hit actor from the Break Hit Result, and its either logging Tundra Rock Formations or nothing. But I am getting the Drop Particles appearing. I’ve done this session twice now with the same results.

[@kuangjuitsou1699]

How do you adjust the water? The waves are too thick by default, can it be more detailed?

[@danielpetrikovic1562]

Hey, I can't seem to find the random range vector in the particles position dropdown menu...

[@redwolf831]

same

[@NikomaGrob]

@@redwolf831 Ever got it fixed or nah? I have the same problem.

[@redwolf831]

@@NikomaGrob I honestly don’t remember sorry

[@nickprice6644]

Well after fixing my other issues, when I walk in the water my particles (ripples) appear as black circles. Help please.

[@yiyanglu-k4n]

Thanks for your awesome tutorial! Just a quick question, in 17:00 there is a ball in the center of my 2d shallow water dropping down constantly, and I have already ticked param in killparticle, Do you have any ideas on why this happened?

[@NumenBrothers]

Yep, you have to hide the actual particle material- I cover that toward the end of the episode, here: kzbin.info/www/bejne/a5K1gIB3Z7CEhsU

[@stijnhernalsteen8209]

To solve the water level issue: Enable dissipate waves near edges and put the unit space falloff at 0.9 or something.

[@NumenBrothers]

Didn't work for me unfortunately. Created a permanent 'ripple' near the edge that grew with time

[@Cryofluid]

Excellent! Thank you!

[@redwolf831]

I don't see the random range vector in the particles position drop down menu

[@AmjoodBasha]

Thanks! Question: will this work if I use it for interactive puddle (big ones) and areas with water in an area in my scene? Or do you recommend some other way?

[@NumenBrothers]

this is exactly how I would do that. Should work for even a large puddle. And if it's a puddle you don't need to worry about the postprocess volume underneath.

[@AmjoodBasha]

@@NumenBrothers You are wonderful! I am trying out that now, and it coming out super cool! Although the water is kind of extra shining (a bit over) in my arena

[@plasid2]

cool, could you also make river flow, water obstacle rocks etc?

[@TheSebledingue]

I learn a lot from you, thanks a lot

[@NumenBrothers]

My pleasure

[@redwolf831]

Could you do this same effect with the water body custom?

[@nickprice6644]

Hi, I can't seem to see where SM_WaterPlane and MI_Water1 objects are created. At this stage I don't seem to have them Nick

[@nickprice6644]

Managed to find this in 'City Park Environment on the Epic game site.

[@trockenmittel]

How would u do flowable water that can be pumped away

[@NumenBrothers]

Lower the water level Z, and move the pump under the water

[@coolguy-xb2yn]

instead of line traces to detect if you're in the water, why not put a box collision on it, and use a bool "inWater" that you set/unset on overlap/end overlap

[@NumenBrothers]

Yep! That would absolutely work. Not sure of the performance difference between having an overlap volume vs. doing line traces.

[@moegabs]

my water doesn't appear on the preview nor on the stage any ideas why

[@NumenBrothers]

Not sure- but For 3D water I needed to unselect the checkbox for Use Landscape Collisions in the Niagara system. Could be that. Are you referring to 2D or 3D water? If 2D, recompile the materials used in the sprites and see if that works.

[@nickprice6644]

Hi Moegabs, did you manage to get this working, as I have the same problem. Nick

[@SilverWolf-VR]

Try this, it worked for me! For 3D Niagara system; Open the Niagara System and search in the User Parameters tab for 'Height'', try adjusting the Water Height, mine started showing at around 3000 Hope this helps!

[@redwolf831]

The center of my water is spawning, a bunch of gray spheres

[@studiobaxter1242]

Did you use 'retriggerable delay'? I had the same problem, but switched back to 'delay until next tick' and the spheres disappeared. The reason I used retriggerable delay in the first place was because I was getting flashing in the editor, but then I noticed it doesn't happen in play, so it's fine.

[@vidmaster7]

Okay, I'm just going to brag a bit. I built a beast-of-a-machine and my FPS with the 3D Niagara water is 74fps and without it 120fps. 😀

[@NumenBrothers]

lol

[@NiciAngelPlay]

19:00 😅💚

[@MilanKarakas]

First. LOL