WoW: Forever's graphics, explained

What changed, and what stayed

The models and textures stay. Blizzard's rule for Forever's look is that everything must be authentic, "Azeroth as you remember it", and the art team treats the original vanilla assets, with their edge and grittiness, as the foundation. What changes is the rendering around them: fog, lighting and water.

It isn't a filter. At BlizzCon's Evolving a Timeless World panel, the art team said they rebuilt each zone's lighting from the ground up, using the original 1.12 client as reference for every time of day, from midnight to sunset. On the 22 October podcast, the developers said it started with one test area around Northshire Abbey, where they tried new lighting, fog and water. Seeing Darkshire with its new fog and lighting won the team over.

Volumetric fog and longer views

Vanilla's distant fog had a technical job: it hid the edge of the draw distance. Forever replaces it with volumetric fog. Each zone has its own fog and its own wind, there can be pockets of fog you walk through, and light can shine through it. The rays you see in Ashenvale come from light scattering through the fog, shaped by whatever casts the shadow.

Freed from the old wall of fog, the views open up. From the Barrens you can make out Durotar, Azshara and Nordrassil on top of Mount Hyjal. From the Wetlands you can see the Violet Citadel of Dalaran in the Alterac Mountains.

Shadows that follow the sun, light that bounces

In the original game, the sun and moon in the sky didn't match the light falling on the world, so a tower's shadow stayed put all day. In Forever they line up. Mountains and terrain now block the light, so dawn breaks over a ridge in the Badlands and tree shadows in Mulgore move through the day.

Flat ambient light is gone too. Forever uses global illumination: light bounces off surfaces and picks up their colour, so red light off a roof tints a chapel wall, and the inside of an Elwynn stable is properly dark. Blizzard built its own ray tracer for it, and its lead graphics engineer said it runs on the minimum hardware requirements, not just the recommended ones.

Water, rain and the sound of the roof

Water got a new shader. Waves change with the size and depth of the water and with each zone's wind. Rivers now flow along their course, bend around rocks and foam where they hit them, and a few magical ones run uphill. Artists can set water anywhere from murky to clear, and it now reflects the whole scene, including the sun and moon.

Weather came later, during the beta. On 23 September, Blizzard said increased weather effects were coming to some beta zones, and showed rain in Elwynn Forest kicking up mist near the ground. Step indoors and the rain changes: it sounds different depending on the roof above you. On the podcast, a developer guessed that touch came from a sound designer who thought it would be sweet, the kind of thing the team is free to add.

Duskwood, rebuilt light by light

At BlizzCon, the team lit Darkshire's square step by step to show how a zone comes together. Moonlight alone was too dark to play in, so each layer adds back just enough.

The result is a darker forest under the trees and more fog over the farms. If you want to see where you're going, the Night Watchman's Torch from Raven Hill lights the way.

1. Moonlight over the bare models and textures.
2. Point lights on every window, torch and lantern.
3. Global illumination, to lift the shadows and add colour.
4. A base layer of fog, then moonlight scattering through it.
5. Moving mist and ground fog.
6. Bloom and colour correction, then pulled back until it still looks like Duskwood.