Hey,

I have another interesting challenge for you folks on Polycount. It helps if you're familiar with the the game in the title but I'll provide a gif of a waterfall below. I'm trying to recreate this flowing water effect and I'm wondering if you can help me nail the material network down. Obviously we have a panner for the middle section but it's the pointy bits at the top and bottom that have me puzzled.



I look forward to seeing the replies.

I think it's just a horizonal panner with a tiling wave texture on it layed over using another alpha plane. Vertical waves offset could be done with some kind of vert painting shader. Can't rememther the ins and outs of it, but it looks like this!:

Beating Heart UDK - YouTube

Or it's just an angled alpha plane with another panner on it wedged into the edges.

Hey, this is just one tileable texture for the water flow, the edges on top and bottom are just probably animated textures with alpha. The corners also have animated white water alpha going on. I dont think there's much secret about it. Specially that this game is unlit the whole way, or just vertex painted. Still lovely game, I miss it.

How I'd do it:

Panner->Rotator (or vice versa)->mask channel R->a noise/clouds texture->take one of the channels->use IF against the G channel of our UVs->white or blue.

I was bored so I got out my laptop (which can barely run UDK) and roughed the edging and as a bonus the splash at the bottom.


It's not exact but not far off.

I'll upload the package in a bit.

http://www.smallfiles.org/download/3...kerFX.upk.html

Thank you so much. You're going in the credits of my project when it's done.

I just want to say man that the water fall you got going is still awesome, looks like a good and fun project can't wait to see more.

you could always just use a flipbook texture for that true .gif feel...

What is the bit of code in the custom node doing? I don't quiet understand. How is it bending the U and V into a radial?

Can you break down what each part of the equation is for? I'm mostly curious as to what the atan2 is.

Atan2 takes a X and Y and returns the angle around 0 as -pi to pi. I'm also doing some addition/multiplication in there too just to get the scales/offsets right.

You guys are totally overthinking the Zelda water. Those "spikes" are just two copies of an alpha mask, scrolling in opposite directions. The mask image is low frequency waves, with a few larger "spikes" in it. As the two scroll, the "spike" waves cross over, causing the bigger spikes. You can really see it if you pick a spot in the scroll and follow it with your eyes as it pans - it will reveal the two layers.

Keep in mind, the Gamecube used very limited pixel shaders. It wasn't very fast. Computing arc tangents per pixel would likely be prohibitively expensive on an actual Gamecube.

While that doesn't apply as much to today's graphics processors, it's a good idea to keep up the same mindset. The more reuse you can get out of your shaders, the better off you'll be. You don't want infinite different shaders for every new object or effect, for the sake of batching, resources, etc.

If you can accomplish something with a simpler shader, do it

You could quite easily work around the atan using a triangle fan. If you look at the slight segmentation on the ripple that's probably how they did it.

Originally Posted by Slum

You guys are totally overthinking the Zelda water. Those "spikes" are just two copies of an alpha mask, scrolling in opposite directions. The mask image is low frequency waves, with a few larger "spikes" in it. As the two scroll, the "spike" waves cross over, causing the bigger spikes. You can really see it if you pick a spot in the scroll and follow it with your eyes as it pans - it will reveal the two layers.

Keep in mind, the Gamecube used very limited pixel shaders. It wasn't very fast. Computing arc tangents per pixel would likely be prohibitively expensive on an actual Gamecube.

While that doesn't apply as much to today's graphics processors, it's a good idea to keep up the same mindset. The more reuse you can get out of your shaders, the better off you'll be. You don't want infinite different shaders for every new object or effect, for the sake of batching, resources, etc.

If you can accomplish something with a simpler shader, do it

QFT

EDIT:
OK what I would do more specifically, is use a lerp to separate the flowing water texture, and constant3V for the solid color.
For the Alpha for the LERP, I would use an RGB texture, no alpha, and place my jagged masks in the R and G, and use the B for the edges. Pan those R and G channels into a multiply, then plug the multiply into the lerp alpha.

How about this? No ifs, no atans, just one texture sample and some scrolling with a multiply for falloff, the mapping to a "tunnel" shape done by a triangle fan.

This gives me an idea for contests, we should have mini shader comps on who can do a shader with the least instructions, and who can do the best looking one with a maximum limit.

Hey guys, I did it.

UDK - Wind Waker style waterfall material -...

Texture sources:

Waterfall BG
http://i.imgur.com/evAPk.png

Current 1
http://i.imgur.com/Gl1ZQ.png

Current 2
http://i.imgur.com/lGiUj.png

Splash
http://i.imgur.com/Jdv9M.png

Here's the whole material






He's the branch that repeats 5 times (I just copied it from JamesWild), 3 of them have different uv sets, the 2 current ones over lap and use the same UV, different speed, the top splash is 2 splashes going in opposite directions and mirrored.






And this is how it is all put together in the end




Any questions?

It's nice ZacD, except for the parts at the top and bottom. I can notice the textures panning, where in the original, it's more "wavy" instead of "panny". If you could tweak it a bit, it would be awesome.

I believe, in the original there is a separate mesh on top of the 2 meshes going opposite directions, that causes those big bouncy spikes, but there is also the 2 crisscrossing textures like I have. I could try to add a third layer to the spikes, and tone the 2 I have down a bit, and there's also some vertex offset going on in the actual game as well. Before doing anything more to the material I'd want to jump in game, and it'd also depend on the scene I was creating.

Hah I never expected this to continue.

Hey James, could I be cheeky and ask how you would do the wind effects? It's a sort of single line with points at both ends. In other words it's a scrolling, fading white texture with points on each end. I'd get a video but there's not one that really shows it. You have to look up a video of gameplay.

I did play Wind Waker end to end a few years ago (actually the only Zelda game I like a LOT) and I think I know the one you're talking about. Could probably pull it off with a white emissive, and two multiplied very small images. Hang on...

http://www.smallfiles.org/download/4...ater2.upk.html

Thanks man! I look forward to sharing what I've applied your shader to but there's still a few things left to do before I can showcase it.

Hey again, sorry to be a pain but your wind effect is almost there but not there. Well in regards to speed anyway. I've messed around with the numbers but I can't get the perfect speed, flow and fade.

Here's a video of the wind, check 5:16 in the background and I suggest you mute, loud mouth guy playing. Look behind her head for example, speed and fade.

Let's Play The Legend Of Zelda Wind Waker, Part...

On the bright side you can scale the static mesh along the z axis to make it thin like in the vid.

Also don't forget to oscillate the spikes in the light blue jaggies. Notice they are pulsing up and down which helps to hide the panning effect.