When comparing Unity vs Skyline, the Slant community recommends Unity for most people. In the question“What are the best 3D game engines?” Unity is ranked 3rd while Skyline is ranked 25th. The most important reason people chose Unity is:
Unity3D provides an exhaustive documentation where everything is given a full description supplied by a number of examples as well as video and text tutorials and live training sessions to understand the ins and outs of the engine. In addition there's an ever-growing community that can offer advice to help resolve any situations that may arise. Along with the official Unity resources, there are [many high quality](http://www.slant.co/topics/346/~beginner-resources-to-learn-unity) (and often free) third party tutorials available.
Ranked in these QuestionsQuestion Ranking
Pro Lots of resources to learn from
Unity3D provides an exhaustive documentation where everything is given a full description supplied by a number of examples as well as video and text tutorials and live training sessions to understand the ins and outs of the engine. In addition there's an ever-growing community that can offer advice to help resolve any situations that may arise.
Along with the official Unity resources, there are many high quality (and often free) third party tutorials available.
Pro Easy learning curve
The way the editor is structured, by setting scripts on objects, and the use of a high-level language, C#, makes it easy to learn.
Pro Lots of assets can be found in the Asset Store
For those developers who can't afford an artist, or aren't skilled enough to create their own art, Unity features an Asset Store full of a wide variety of free and paid assets that can be easily added to a game. The Asset Store has more than just music and art. It also has code and modules that can be added to games including unique lighting or GUI systems. It also has powerful asset management and attribute inspection.
Pro Allows for rapid prototyping
Unity's modular system and usability allows for quickly developing a prototype of an idea. It has features like drag & drop editing, shaders, animation and other systems already in place to allow diving right into developing a game.
Pro Very popular
Unity is a proven game engine. It is used by a wide range of developers - from small indies to triple-A companies such as Microsoft, Paradox, Square Enix and Sega.
Pro Great editor
The editor GUI is very powerful and intuitive. It allows pausing gameplay and manipulating the scene at any time as well as progress gameplay frame by frame. It also has powerful asset management and attribute inspection.
Pro Free for mobile development
Unity allows free mobile development. There are some limitations.
Pro Can be used for free
As long as the development company makes $100k or less, it can use the free version of Unity to release games.
Pro Has awesome plugins
Pro Over 20 platforms
Unity offers over 20 platforms for publishing including mobile, console, web, VR, and more.
Pro Works with 3rd party IDEs
Pro Has a great animation system
Unity provides a great state machine animation system called Mechanim allowing to separate animation from the model and assign the same animoations to different models.
Pro Very optimized
Unity runs very smoothly even on systems that are considered "weak" by today's standards.
Pro OUYA support
Pro Powerful standard shaders
The built in standard shader in Unity 5 is incredibly optimized and supports PBS/PBR.
Pro Can create custom forms and tools
Pro Offers choice of scripting languages
Pro Flexibility is provided by a strong component programming model
Pro Great tech support and friendly community
A growing community that is always helpful with dev response times averaging less then 24 hours. Often less than 12.
Pro Comprehensive WYSIWYG editor
Skyline provides a straightforward drag and drop development environment that can be customized to suit individual preferences. Playing the game and animating the scene can be done from within the editor at any time.
Future versions will allow extending editor's functionality with plugins and offer an official way of trading custom plugins.
Pro Highly affordable licensing
Skyline's commercial edition costs just £40, has no royalties or earning limitations and includes 2 activations per license purchase and a year of free updates.
Pro Runs well on lower end machines
Skyline can be run on a machine with 2GHz Dual Core CPU, 2GB of RAM and Nvidia's 9800 GT (or equivalent) GPU. While, obviously, higher specs are recommended, it's reasonable to expect around 60fps on small scenes with these specs.
Pro Excellent terrain editor
The Terrain editor is easy to use and will include features such as hole cutting.
There is a differed lighting render for internal scenes, which makes creating multi light and beautiful/atmospheric scenes so much easier.
All the tools for the terrain are in one place such as placing road/paths, vegetation, billboards, and the settings are easy to locate and change.
Planned features include:
Hole cutting in terrain and
Pro Low learning curve
Making a game in the current top engines is hard work, making something small and basic in Skyline is not. Easy to learn drag an drop model placement and editing supplemented with easy to follow video's on forum make the process straightforward.
Pro Full global illumination
Including image based lighting.
Pro Has a free version
A free version that's limited to non-commercial usage and lacks a few features is available.
Pro Impressive water render
Rendering of a water plane looks fantastic and is easily edited for different effects.
The schematic editor is designed to make it easier for non-programmers to create games.
Pro Asset store
Not much in it at the moment but is starting to grow and will continue to grow with an increase of users.
Pro Constant development and regular updates
There are many additions to the engine that are on the road map such as multi threading and tree physics.
The feature list is constantly evolving with each user request and idea put forth.
Pro Support for custom editors
Skyline has a custom editor that gives the user of making their own tools for use directly in the editor to develop their games. All the editors are made using the Qt Designer and programmed in lua inside the engine itself.
Pro OSVR support announced
Open-Source Virtual Reality support is in development.
Pro More editor's
Weapon Class Editor.
Advanced Mesh Editor.
Environment Editor (volumetric clouds and day night cycle, lightening, ocean settings, height fog).
Pro Lots of learning resources
The documentation is been rewritten and follows a structure like a course.
Introduction to > Level designer with examples > Artists
There is also video tutorials, video examples and video tutorial series been produced.
There are user created demo scenes, examples and more.
Pro Visual GUI/HUD Dditor
Making HUDs and GUIs has never been easier
Pro PBR Workflow
Full PBR workflow, your not stuck to Secular or Metallic it has both
Pro One on one private support with engine developers
Can contact the Skyline developers and they will always respond and help as fast as they can.
Con Hard to maintain projects due to vendor lock
Unity3D is proprietary, closed source game engine. Unity asks money for features like basic version control support, etc. It is impossible to migrate a game from Unity3D in case performance does not satisfy growing requirements of a project.
Con Very bad terrain
Native terrain creates a lot of draw calls which is bad for performance.
Con Weak memory management
.Net libraries are slowing it down, memory safety is compromised, classes have to be implemented to manage objects in memory, like object pooling.
Con Garbage collection can't be turned off
Given the use of C#, the memory control is out of the developers control, this can be good, but not controlling memory means that the garbage collector can trigger at any time and ruin performance.
Con Adds too many features without fixing earlier issues, rapidly increasing number of bugs that will never get fixed
Unity continues to add many new features without fixing earlier issues. Unity is either understaffed, overambitious, or both, resulting in a continual increase of problems and degraded experience across a number of platforms. Many bugs are reported daily and never get addressed, and there are many bugs from previous versions that are never looked at or fixed.
Con Very self-centered engine
Unity3D uses very unique approach for doing things. Most of the knowledge acquired while using it, would be completely non transferable to other engines. Advanced Unity3D programming is really dealing with Unity3D bugs, and finding loopholes around engine issues - nothing to do with graphics, etc. Skills which would be valuable with other engines.
Con Encourages bad coding practices
A lot of Unity code feels like a hacked blur of arguable coding practices. C# and .Net usage in Unity is questionable. A lot of the API is done in "C Style" (public static methods, available at all times), encouraging the use of public fields for everything, a lot of questionable implicit casting. The list goes on.
Con Increasing number of bugs
With each new version things may stop working ,for example with Android, some bugs are never getting fixed, like the freeze bug with adb.
Con Bad batching support
Draw Call Batching is done automatically and does not include Skinned Renderers (eg. characters). Also for dynamic batching, meshes need to have less than 900 vertices.
Con Mobile builds (Android, iOS) take about 18MB at least
Even a Blank Project, Needs 18MB for the APK file (on Android).
Con Price is very high
Cost is based on Revenue:
less than $100K = Free
between $100K and 200K = $35 a month per seat
greater thank 200K = $125 a month per seat
Con Moderators on forums are sometimes arrogant
Con Dark UI theme not available in the free version
Dark theme, which is a must for prolonged work without eye strain, is only available with one of the paid monthly plans.
Con Limited 3D modeling capabilities
While Unity itself lacks proper 3D modeling capabilities, tools such as ProBuilder or MXD are available in the asset store that add that functionality within Unity.
Con Bad raycasts
Con New il2cpp script backend is show stopper to some iOS projects
Il2cpp script backend is required to build arm64 app, but it's still very buggy and not production ready.
Con Asset bundles can be cumbersome
Asset bundles are a way to load external resources that are not packed with the game or application and offered as a separate, optional package. However, they may not be compatible between versions or even platforms (you have to create them separately).
Asset bundles need to be loaded and unloaded, avoid concurrent loads from web or cache or a naming collision can happen. You can find workarounds with static objects (load
obj files and textures by code), but for animated game objects you are pretty much stuck with this.
Con Docs have inconsistent choice of scripting languages
Con Comparatively high learning curve
Although C#, JS, and Boo have documentation available online, it can still be difficult to understand the library and Unity's component based system.
Con Boo and UnityScript don't have many learning resources available
Con Variety of scripting languages complicates compilation order
Con Bad model importing
Con Bad input
Con No C++ SDK
Con Still in beta
Not all features are fully implemented yet.
Con Small community
There is a small but helpful community that are constantly creating video tutorials and one member is creating a FREE ebook to make the transition to the engine simpler.
Con Currently limited to targeting PC
Mobile targets are planned.
Con Free Version currently not available/severely limited when available.
The free version has massive amounts of features functionality removed, including the ability to compile anything standalone.
The free version is currently (as of November 2017) not available until the next major release.
Note: some of what is below is open to change, this is the coming set of changes.
The price will be jumping from $40 to £99.99 ($132.32) for the lowest tier able to build a standalone. This tier will not be able to remove the engine splash screen.
The next tier will be £199.99 ($264.66).
Con Lacks occlusion culling and lightmapping
This is been added in a future update, however a date of this update hasn't been given yet.