Miglbélere

Alright! Let's actually talk about this waterfall thing. It is an amazing showcase of many things that I adore from late 90s graphics. I am replicating this in Blender, through mere observation of the final game, so some things might not be exactly accurate to what the PS1 does.

First off, this is what I started off with, straight from the Noesis exporter into Blender.

"Looks boring!" "What are those weird gradient quads?!" Oh we'll talk about those too, don't worry.

Let's start simple, figuring out the Layers.

We've got the base level geometry, then two layers of water, each with a different texture.

Let's focus on the bottom Water layer first. A waterfall's water falls, and the age old trick to replicate that behaviour is to scroll the texture along the mesh by offsetting the texture coordinates every frame.

Simple enough. Not too convincing yet.

Let's do the same with the other layer.

Look at it goooo!

An often-used trick to enhance the waterfall effect is to increase the distance between vertices (or squash texture coordinates) as the geometry goes down.

This affects the scrolling velocity for the texture in each section, making it look like gravity is accelerating the water.

MGS pulls yet another trick on top of that:

Vertices are subtly animated to oscillate, making the water flow seem more irregular.

It seems to be something similar to what is done to geometry when the camera goes underwater in the docks or vents area.

One opaque layer of water on top of another is no good.

Alpha Blending is an expensive technique and it'd not give the desired effect.

Additive Blending is used instead. The lower layer is rendered first, the second layer is then rendered on top, adding the color values together.

Now we get to talk about those weird quads.

They are darkening gradients! Instead of using Additive Blending, they do the opposite, the color value from the texture is subtracted from the scene that was rendered below, effectively creating shadowed areas.

Who needs HBAO+ anyway?

Lighting pass!

I just threw a few point lights to try and replicate the original vibes of the scene.

MGS, instead, uses lighting information baked into the vertices of the scene to create this mood. And what a mood it is!

Here's an additional example of the same techniques used in the bottom part of the same scene. Although the game seems to be rendering that water mesh as (almost?) completely opaque, there is an actual floor mesh under it.