Unity Technologies has lifted the lid on the upcoming Unity 4, a major upgrade to the game development platform that currently claims over 1 million registered users. The upgrade brings an increase in visual fidelity to Unity games, DirectX 11 support, an enhanced exporting option to Flash, a preview of game deployment to Linux, and more. The biggest change Unity is touting for this latest release is the addition of Mecanim, a suite of animation tools the company acquired last year. Mecanim allows developers to create animation blend trees and state machines within Unity itself. We haven't seen it ourselves yet, but over the phone Unity CEO David Helgason tells us that it's "super high performance," and that developers using it as part of a beta program have been impressed by its polished workflow. "It solves a lot of things completely automatically, and figures out a lot of the beginning and end times, and how you group things, and so on," he says. "Copious amounts" of animations for Mecanim will be available in the Unity Asset Store on day one, Helgason tells us. With DirectX support, Unity 4 games should see increased shader capabilities and smoother models and environments (via tessellation). The company says mobile platforms will also see a boost of fidelity thanks to new features and optimizations. Promised improvements include real-time shadows, skinned mesh instancing, normal map baking, and a refined GPU profiler. The release also finally brings Flash deployment, introduced in beta form last year, to a fully functional release. It also adds a preview of deployment to desktop Linux machines. Additional features to be available in Unity 4.0, according to a list provided to us by Unity, include:

Helgason says that upgrades and feature additions to Unity 4 should come at a quicker pace than they did for 3. "Even with 8 or 9 releases in under two years…we feel like we haven't been doing enough and actually want to speed up our releases. The goal is to only have a small handful of months between release dates." A release date for Unity 4 has not been set, though interested developers can pre-order it here. A demonstration of Unity 4 will take place at the Unite 2012 developer conference in Amsterdam this August.