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What OGRE is, what you can do with it and other frequently asked beginner questions

What is Ogre?

OGRE (Object-oriented Graphics Rendering Engine) is an open-source graphics rendering engine that is written and maintained by a small core team, and contributed to by its ever growing community. Those of us that use it believe it's one of the better free and open engines out there today, but don't take our word for it - try it out for yourself.

Who are the developers?

Well, let The official Ogre Team page answer that particular question.

What tools and hardware do I need?

Ogre runs on a wide variety of hardware capable of 3D graphics, although performance will certainly vary. Look at the Hardware page to see graphics hardware requirements and recommendations.

As far as tools are concerned, you will need a supported C++ compiler (e.g. VisualStudio or Code::Blocks/MinGW).

Finally, you will need an arsenal of 3D programs to create content. Look at Assembling a production pipeline to learn what other software is needed throughout the process. The most basic and commonly used one is an object modeller.

Do I have to know how to program to use Ogre?

Yes, you will need to know how to program. Ogre is not a game shell or scripting language like many game development kits out there. It will require more knowledge to use properly, but it is also many times more powerful than a scripting kit will be. A good knowledge of C++ is essential, as is an understanding of object-oriented programming. Ogre's power means that it's not something readily suited to someone who is just looking to start programming. That's not to say you can't learn to program by using Ogre, but it will be many times more difficult than if you were to start with a more traditional approach.

Can Ogre only be used with C++?

No, there are various wrappers that offer the possibility to use other programming languages than C++. However, these projects are not officially supported by the Ogre Core Team.

There are currently Ogre wrappers for Python (Python-Ogre), Java (Ogre4j) and for .NET languages - C# and VB.NET - (MOGRE). Test

Where can I learn how to program in C++?

There are thousands of websites and books that can teach you the needed programming skills in order to start with Ogre. Some are listed below, but don't consider this the ultimate collection, but find out yourself with which resources you can work the best.

Websites:

• Complete C++ language tutorial
• C++ Programming Tutorial
• C and C++ Programming
• C++ FAQ Lite

Introductory Books on C++:

• "C++ for Dummies"

A note to newbies. Knowing 'how' to program C++ (such as syntax, etc.) does not help you actually create a sophisticated program. Ogre will bring you a step closer to creating a 3D program, but you still need a lot of practice.

Is Ogre a game engine?

No. This is a subtle distinction that a lot of people tend to miss. Ogre is a graphics engine, and only a graphics engine. However, it can easily be tied together with other libraries to create a game engine. Some libraries you might need to create a game are:

• Sound
• Networking
• Input
• Collision

Ogre does not include these libraries natively, although it does expose an interface that makes it easy to work Ogre into an existing application. There are several reasons that Sinbad (the lead developer) has chosen to follow this route. I'll let him speak. This is from a forum post from sinbad.

''OGRE is a component in a larger development system. OGRE is not, and never was, intended to be a one-stop-shop game development platform, it's a tool for a specific purpose. I sometimes have to rabidly defend this because it seems I go against the grain of other engines, who concentrate on providing an all-in-one solution.

I think software systems should be modular and pluggable, with clear interfaces and boundaries between them. I think each team should concentrate on their core area and let others get on with specialising in theirs (I think it's pure madness to try to reinvent ODE for example, as some other engines are doing). I think the most important part of any software system is it's interface, to support all of the above. I think developers should be free to combine the tools they choose into their game development platform, not be told which sound, physics, AI etc implementation to use just because they chose a graphics engine.

I realise this approach means that as of today, it's not as fast to develop a game with OGRE than it is with another all-in-one engine. But I'm not just thinking about today. My philosophy is to build a flexible graphics component which can be used in the maximum number of situations, and to make it easy to integrate with other components - not to build an engine that can be used to make a small number of game variants. I favour flexibility over speed, because I think if you design it right, you can add the tools to make it quicker to develop in specific scenarios later. You'll find it a lot harder to extend an engine which is designed to handle only a small subset of scene types, with strongly integrated features designed from a certain perspective. I try to plan for the long term.

As time goes on I expect more 'combination' solutions to evolve naturally, and indeed that's already happening with people building their own platforms based on OGRE and other libs. Hey, maybe I'll produce my own one day which combines OGRE with my choice of sounds/network/physics libs. But my choice doesn't have to be your choice. I think that's important.''

Note that this doesn't mean that you can't use Ogre for games. In fact, it's probably going to be used for games more than anything else out there. This simply means that Ogre doesn't decide what libraries you're going to use, and allows you the flexibility to fit Ogre into your application, rather than attempting to wrap your application around Ogre.

Can I use OGRE to produce graphics too?

Ogre is a realtime rendering engine. Many of the pictures on cgtalk and other sites are rendered offline or slowly, often with ray tracing. The technology of the two are fundamentally different. One can make offline rendered pictures as detailed or realistic as one has the time to process each image. It may take several hours or longer to generate a full screen image. With realtime rendering, each image is rendered in say 1/30th to 1/100th of a second for a decent framerate. Nevertheless, the strides being made in current 3D graphics hardware have allowed realtime rendering to become very detailed and realistic looking. Ogre is bound by the hardware you run it on and your imagination. For a look at what kind of graphics you can expect, look at the images NVIDIA and ATI use to sell their graphics hardware.

Our Ogre Gallery has many screen shots that show the capabilities of the engine and graphics hardware. Some shots are impressive by themselves. Others are less so, but show a specific feature that could be used to provide powerful and flexible effects, such as post filtering, fresnel refractions and normal mapping.

Ok, you've convinced me. How do I get started?

These links are available from the Main Page as well. First select if you want to Install An SDK or Build From Source. The latter option is for those experienced in C++ development. Then move on to Setting Up An Application and Ogre Tutorials to get going.

I'm stuck! How can I get some help?!

Your main resources for information are the pages on this wiki including Installing An SDK, Building From Source, Setting Up An Application and Ogre Tutorials. The API and manual are necessary references as well. If your questions aren't answered there, Ogre has a thriving community full of helpful people, who will be more than happy to help you out. You can try the forums - most all of your questions will be answered there speedily, but read the forum rules, then use the search function! Most questions that new users ask have been answered countless times before. Make sure to provide relevant details from your Ogre.log, exceptions, error messages, and/or debugger back traces. Be specific and people will be more able to help you.

If you'd like something a little more interactive, connect to irc.freenode.net and join #ogre3d, and we'll get you patched up in no time!

What file formats does Ogre support?

Ogre supports a number of common file formats, but also makes use of Ogre specific file formats.

Common file formats supported:

• .bsp Quake bsp file
• .shader Quake 3 shader file
• .ttf True type font file
• .png, .tga, .jpg, .raw, .gif, .dds and more as supported by FreeImage. See A Brief Summary of Image File Formats
• .cg Cg shader file
• .asm Assembly shader file
• .zip Packed resources
• .xml XML file
• .xsd XML schema file that defines Ogre specific file formats that are XML based
• .log Text output file used for debug logs, memory logs and memory leak reports

Ogre specific file formats:

• .material Ogre manual: material scripts
• .compositor Ogre manual: compositor scripts
• .particle Ogre manual: particle scripts
• .overlay Ogre manual: overlay scripts
• .fontdef Ogre manual: font definition scripts
• .skeleton Binary file containing skeletal animations.
• .mesh Binary file containing single mesh definition.
• .scene XML based file with multiple meshes. See DotScene
• .cfg Configuration file for multiple purposes
• .inc Overlay templates include file
• .scheme XML based GUI file
• .imageset XML based GUI file
• .layout XML based GUI file
• .font XML based GUI file

Note that the Ogre does not strive for an exhaustive support of all kinds of common file formats, but instead provides Ogre specific OGRE Exporters for popular digital content creation tools.

Can I make a game with Ogre?

Yes, you can. Unlike many other 3D engines, Ogre isn't geared towards any one kind of game. Due to its design, it can be used for everything ranging from flight simulators to first person shooters to "2.5D" games. If it can be done in 3D, chances are Ogre is capable of doing it.

Can I make an MMORPG with Ogre?

Theoretically yes, but MMORPGs require huge amounts of time, work and money to build and maintain. Just consider that when designing your project. MMORPGs are the hot item these days, and everyone is working on one. However there are very, very few that ever come close to completion. Conventional wisdom says to make at least 2 or 3 smaller "classic" games such as Tetris, Pong, etc. before even attempting something on the scale of a MMORPG, since it will give you a feel for the entire game design and implementation process, and show you how much work it is to produce even a small game. The "everyone and their mother is making an MMORPG" theme is something of a joke in the game programming community, so be forewarned that you may be met with a little skepticism when you announce that your next huge project is going to take the gaming world by storm.

If you are past that and are still convinced that you want to make an MMO, start out right. First, consider joining another team. Most likely, your great idea isn't all that revolutionary. Combining efforts will give the best chance at achieving actual results. If you are still convinced to start one yourself, start with research and more research. Once that is done, research some more. Do not start recruiting on the Ogre forums, that is a bad idea. Once you are confident with what you have learned through research, start a design document. Get your ideas in order and then start to try to get support. Gamedev.net has a recruitment area that sometimes allows newbies to get away with I-want-to-make-an-MMO-from-scratch threads, but the Ogre forums aren't so forgiving.

If you are ready to begin, pick the best tools for the job. Check out Realm Crafter, Multiverse, Project Darkstar or any other MMO engines that may be what you need. If you are still decided on Ogre, be ready for a LONG journey. Expect ridicule from other devs on Ogre's forums. Get a thick skin and believe in what your project is about.

Lastly, never stop learning. It will take you a long time. You will need to get help and start a community for support. If you have any questions, ask, but ask in the right way, with the best grammar and spelling possible. Most people will not take you seriously as it is, so try to dissuade their ridicule by being professional in the way you do things.

There is a lot more to it than this, but this should get you started if you are crazy enough to try.

Alias: GetStarted