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I am aware that game engines like Unity, Unreal, Cry Engine provide almost all the tools necessary to build an AAA title game. Its also the best choice if the game has a tight release data or if your new to game development. But since they are generalist game engines (meaning that they are made to fit multiple genre of games. Correct me if in wrong) for some games (next-gen or games which require a lot of performance), they might leave some performance on the table, something which could be accomplished by developing a custom engine.
This brings me to my question,
Do game developers (indie game developers, large teams or even companies) still build game engines from scratch to tailor fit a game or a game franchise?
Thank You!
when we talk about big companies like Ubisoft or rockstar they built their own engines and didn't use Unity or unreal
Rockstar uses "Rockstar Advanced Game Engine"
and Ubisoft uses "AnvilNext"
but why?
there are millions of reasons they do such a thing, I'm gonna say just 2 from #scremyCat
the support
and the license
Support: Highest degree of support and understanding - as they built it all, they understand all of its internals and can offer
complete support. E.g. A game needs X feature, they'll easily know
if they can implement it or not. Another benefit of this is not
having to wait on external entities, if there's a game breaking bug
in the engine they can get right on it, while a third party engine
depending on the licensing agreement this might not be possible
(though they would typically license the source code anyway).
License: Licensing - as an indie developer accepting that you might have to pay a small percentage of your revenue for licensing
the engine might not be as much of an issue seeing as the amount you
need to breakeven is unlikely going to be very high and chances are
you're already making when your revenue is at the levels needed to
pay a %, and your total revenue from a game isn't likely going to be
huge anyway so the amount in licensing fees you need to pay may seem
very reasonable. Meanwhile a AAA game will have a much higher
break-even target and their expected revenue is most definitely in
the tens to hundreds of millions, which now means they're paying a
large amount in licensing fees. Now it should be said they usually
get much better licensing deals to begin with than the indie dev
gets, but still they're paying huge amounts.
As for timeframe, it can take years to fully develop an engine of their scale. Often why you'll see them using the same version of the engine for a good cycle of games whilst working on the next version of the engine. And as for what's involved, a LOT. They need to handle every platform they'll be targeting, the rendering, the physics, the AI, the audio, the input, the file system access, the asset management pipeline, the tools, etc.
How are they better than current popular engines? They aren't necessarily (to other developers), but to them with their own reasoning for doing it they are. The simplest answer for how can they be better is that when you're creating your own engine from scratch you can do whatever you want.
It should also be said that developing your own engine isn't just limited to large game companies, a number of smaller developers also do this. The more popular reasons for this are typically because they enjoy it, and have some functionality they want that isn't available in existing options. E.g. While you can create many games with Unity or Unreal, there's plenty of things which just aren't feasible or might take considerable work to even make possible anyway. This can be a reason for a smaller dev to make their own engine.
Yes, they absolutely do. Nintendo is a good example.
I want to create a application which converts 2d-images/video into a 3d model. While researching on it i found out similar application like Trnio, Scann3D, Qlone,and few others(Though few of them provide poor output 3D model). I also find out about a technology launched by the microsoft research called mobileFusion which showed the same vision i was hoping for my application but these apps were non like that.
Creating a 3D modelling app is complex task, and achieving it to a high standard requires a lot of studying. To point you in the right direction, you most likely want to perform something called Structure-from-Motion(SfM) or Simultaneous Localization and Mapping (SLAM).
If you want to program this yourself OpenCV is a good place to start if you know C++ or Python. A typical pipeline involves; feature extraction and matching, camera pose estimation, triangulation and then optimised using a bundle adjustment. All pipelines for SfM and SLAM follow these general steps (with exceptions of course). All of these steps are possible is OpenCV although Googles Ceres Solver is an excellent open-source bundle adjustment. SfM generally goes onto dense matching which is where you get very dense point clouds which are good for creating meshes. A free open-source pipeline for this is OpenSfM. Another good source for tools is OpenMVG which has all of the tools you need to make a full pipeline.
SLAM is similar to SfM, however, has more of a focus on real-time application and less on absolute accuracy. Applications for this is more centred around robotics where a robot wants to know where it is relative to its environment, but it not so concerned on absolute accuracy. The top SLAM algorithms are ORB-SLAM and LSD-SLAM. Both are open-source and free for you to implement into your own software.
So really it depends what you want... SfM for high accuracy, SLAM for real-time. If you want a good 3D model I would recommend using existing algorithms as they are very good.
The best commercial software in my opinion... Agisoft Photoscan. If you can make anything half as good as this i'd be very impressed. To answer your question what resources will you require. In my opinion, python/c++ skills, the ability to google well and a spare time to read up on photogrammetry and SfM properly.
What's the difference between physically based lighting, physically based rendering and physically based materials? How they are different from deferred and forward rendering? And physically based rendering is used in films and deferred rendering is used in games?
It would appear that "Physically-based rendering" (PBR), "Physically-based materials", and "Physically-based shading" are different names for the same general concept of creating materials with shading that lend themselves to looking more "real" or physically-based when rendered.
PBR can be used in both movies (offline rendering systems, Pixar has a paper) and games (realtime: Unity and Unreal have docs). It can also be done in WebGL, check out Marmoset's PBR-enabled WebGL Viewer, find the picture of the camera lens, and try rotating that around. Another WebGL example can be found in OpenSceneGraphJS's PBR Demo.
Different PBR implementations have different parameters, but most center around a concept of specifying how "metallic" and how "rough" a particular material is, and allowing the rendering engine to make sure that the material doesn't reflect light in an unrealistic way, or reflect more light than it receives, etc. For example:
This example is a composite of screenshots from the OSGJS demo above, and shows a single base color with varying degrees of metallic and roughness. The idea is that the artist can vary these parameters per-material and even per-texel, and not wind up with something that appears to violate the laws of physics when it comes to lighting. This is considered better than more traditional rendering techniques, where you can create a specular highlight that overexposes objects even in low light conditions.
Disclaimer, I'm still learning about PBR myself. I've been doing a lot of reading up on it lately in hopes of being able to contribute to the current effort underway to add PBR to the glTF 3D model spec. Khronos (the standards organization behind OpenGL and WebGL) is creating an open standard 3D model delivery format that eventually will support PBR, and can convey PBR materials to a wide variety of rendering engines, on the web, mobile, and desktop. But, currently the PBR portion of this is still a draft extension (as of this writing), still under development for some time to come.
I'm not a deferred/forward rendering expert, perhaps someone else can chime in with differences there. In the meantime, I'd suggest to read more from Marmoset about the theory of PBR, and PBR in practice. Good luck.
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I'm a beginner in game development and game programming. I have experience in computer graphics - mainly OpenGL
In those days Finally, I have some spare time to polish my game coding skills.
But when coming to program a simple 3d game, I couldn't find any good resource for free textures and models for 3d graphics (for 2d game for example, I found many resources for sprite sheets and so on).
Is there any good resource you're familiar with for 3d game textures/models?
This is not a programming queston.
As far as I know, good, free and high-quality modeling resources does not exist (from "good", "free" and "high-quality", select two).
There are multiple free model repositories, but quality of content is generally poor, and there are few places where you can buy models.
There are free textures in multiple places (like this one), and they are easier to find than good free models.
Also, most of free content frequently includes some kind of catch - "non-commercial use only", "creative commons share alike"(i.e. if you make derivative, it should use same license), or it is under GPL.
Anyway, if you're okay with "Creative Commons share alike" and GPL, then you can probably use content from some of opensource games (OpenArena ), and get quite a lot of textures from wikipedia or wikimedia commons, flickr, and you can google for "free textures". You should be careful about using content from opensource games - some opensource projects (like war$ow and sauerbraten) use closed-source/restricted licenses for game content (i.e. you're free to reuse modify engine, but you cannot modify game content and you cannot use it with modified engine. Reasons are pretty obvious).
Anyway, it depends on what kind of model you want. It is pretty easy to find "easy" stuff like boxes, barrels, etc, because everyone can do that. When it comes to guns and vehicles, there will be a trouble - quality will drop, and number of good models will decrease. And if you want a fully rigged animated character with multiple animation, normally you can forget about it - such content is almost impossible to find. But you can probably use mods for Q3 and Q2 if you want characters (you can forget about physics in this case, though)
I'd recommend to forget about "free stuff", and try to make content yourself or hire someone to do that.
If you decide to make content yourself, then you'll need digital photo camera and (optionally) graphic tablet. You can make mediocre textures from photos (digital camera is cheap) using gimp, gimp-resynthesizer plugin, gimp-texturisze plugin, high-pass filters, etc. You can also make normal maps using blender or gimp, and there are even tutorials about extracting them from photos (you still will need to process them by hand). Modeling and animation can be done in blender (after 1 or two weeks of training) using reference photos. Low poly modeling is pretty quick (20 minutes to make a low-poly low-quality gun, hour or two to make simple character), but texture and animation will take more (setting up animation for character can take a few hours for amateur, making one animation for character will take at least several hours as well, making texture unwrap - hour, painting texture - up to few days, depending on quality you want, available reference material, availability of graphic tablet, etc). It is possible to cut corners a bit - for example, for making animations, you can film motion using photo camera(or video camera), and then use it for rotoscoping. Also, you'll need to find some kind of model format blender can export to, or you'll have to write an export plugin in python.
The Blender foundation has a large model repository which may be of use.
There are some free models at Turbosquid that I use sometimes for my XNA games.
But of course, the best stuff is not free.
My experience is that there is very little in the way of quality 3d models with animation and full rigging freely available. There a few companies like this who sell suitable models cheaply and I guess most hobbyists could afford one or two models from them fairly easily which would probably be sufficient for learning. (I have no connection to them but I did buy one model pack from them which I quite liked)
It would be nice if there were a few more generally freely available 3d animated models around though. I even think it might be in the interests of some of the companies that make them to give a few away. If I'd been able to get further in my hobby projects I might have spent £100-200 in total on some nice model packs to make my project better, but due to the lack of any real 3d animated models I ended up losing interest in all my 3d projects before I got to the point of thinking maybe I'd spend a little money on this hobby. I wonder if the availability of a few more free quality models would actually significantly increase the size of the market for those companies as more people got their projects to the point where they were willing to spend a little money on it.
Some company should make a nice model pack with a few static models and a couple of fully rigged and animated humans and "monsters" and say that if the community donates £10000 they'll release them for free use. I suspect there are enough people out there who would like a few quality models they might reach this target in the same way that Blender was originally sold to the public.
I know that it's been a long time since this question was asked, but I ran into same problem when programming in XNA and I found a good solution. As long as you don't need rigged / animated models, Google Warehouse is the best place to search. As far as I know, each model submitted to Google Warehouse is available on Creative Commons license. You just need to:
Download and install Google Sketchup (Sketchup download)
Browse to find a model (Google Warehouse) - there's a 3D preview for each one!
Get a plugin to export Sketchup models to .X - I recommend the '3D RAD' plugin (3D RAD download)
If your model does not look good after the export, try to separate it into several less complex ones.
you are looking for open game art ...
http://thefree3dmodels.com/ has a multitude of free 3D models. I've used a few of these for animation purpose, maybe it'll help you too.
I'm a CS master student, and next semester I will have to start working on my thesis. I've had trouble coming up with a thesis idea, but I decided it will be related to Computer Graphics as I'm passionate about game development and wish to work as a professional game programmer one day.
Unfortunately I'm kinda new to the field of 3D Computer Graphics, I took an undergraduate course on the subject and hope to take an advanced course next semester, and I'm already reading a variety of books and articles to learn more. Still, my supervisor thinks its better if I come up with a general thesis idea now and then spend time learning about it in preparation for doing my thesis proposal. My supervisor has supplied me with some good ideas but I'd rather do something more interesting on my own, which hopefully has to do with games and gives me more opportunities to learn more about the field. I don't care if it's already been done, for me the thesis is more of an opportunity to learn about things in depth and to do substantial work on my own.
I don't know much about GPU programming and I'm still learning about shaders and languages like CUDA. One idea I had is to program an entire game (or as much as possible) on the GPU, including all the game logic, AI, and tests. This is inspired by reading papers on GPGPU and questions like this one I don't know how feasible that is with my knowledge, and my supervisor doesn't know a lot about recent GPUs. I'm sure with time I will be able to answer this question on my own, but it'd be handy if I could know the answer in advance so I could also consider other ideas.
So, if you've got this far, my question: Using only shaders or something like CUDA, can you make a full, simple 3D game that exploits the raw power and parallelism of GPUs? Or am I missing some limitation or difference between GPUs and CPUs that will always make a large portion of my code bound to CPU? I've read about physics engines running on the GPU, so why not everything else?
DISCLAIMER: I've done a PhD, but have never supervised a student of my own, so take all of what I'm about to say with a grain of salt!
I think trying to force as much of a game as possible onto a GPU is a great way to start off your project, but eventually the point of your work should be: "There's this thing that's an important part of many games, but in it's present state doesn't fit well on a GPU: here is how I modified it so it would fit well".
For instance, fortran mentioned that AI algorithms are a problem because they tend to rely on recursion. True, but, this is not necessarily a deal-breaker: the art of converting recursive algorithms into an iterative form is looked upon favorably by the academic community, and would form a nice center-piece for your thesis.
However, as a masters student, you haven't got much time so you would really need to identify the kernel of interest very quickly. I would not bother trying to get the whole game to actually fit onto the GPU as part of the outcome of your masters: I would treat it as an exercise just to see which part won't fit, and then focus on that part alone.
But be careful with your choice of supervisor. If your supervisor doesn't have any relevant experience, you should pick someone else who does.
I'm still waiting for a Gameboy Emulator that runs entirely on the GPU, which is just fed the game ROM itself and current user input and results in a texture displaying the game - maybe a second texture for sound output :)
The main problem is that you can't access persistent storage, user input or audio output from a GPU. These parts have to be on the CPU, by definition (even though cards with HDMI have audio output, but I think you can't control it from the GPU). Apart from that, you can already push large parts of the game code into the GPU, but I think it's not enough for a 3D game, since someone has to feed the 3D data into the GPU and tell it which shaders should apply to which part. You can't really randomly access data on the GPU or run arbitrary code, someone has to do the setup.
Some time ago, you would just setup a texture with the source data, a render target for the result data, and a pixel shader that would do the transformation. Then you rendered a quad with the shader to the render target, which would perform the calculations, and then read the texture back (or use it for further rendering). Today, things have been made simpler by the fourth and fifth generation of shaders (Shader Model 4.0 and whatever is in DirectX 11), so you can have larger shaders and access memory more easily. But still they have to be setup from the outside, and I don't know how things are today regarding keeping data between frames. In worst case, the CPU has to read back from the GPU and push again to retain game data, which is always a slow thing to do. But if you can really get to a point where a single generic setup/rendering cycle would be sufficient for your game to run, you could say that the game runs on the GPU. The code would be quite different from normal game code, though. Most of the performance of GPUs comes from the fact that they execute the same program in hundreds or even thousands of parallel shading units, and you can't just write a shader that can draw an image to a certain position. A pixel shader always runs, by definition, on one pixel, and the other shaders can do things on arbitrary coordinates, but they don't deal with pixels. It won't be easy, I guess.
I'd suggest just trying out the points I said. The most important is retaining state between frames, in my opinion, because if you can't retain all data, all is impossible.
First, Im not a computer engineer so my assumptions cannot even be a grain of salt, maybe nano scale.
Artificial intelligence? No problem.There are countless neural network examples running in parallel in google. Example: http://www.heatonresearch.com/encog
Pathfinding? You just try some parallel pathfinding algorithms that are already on internet. Just one of them: https://graphics.tudelft.nl/Publications-new/2012/BB12a/BB12a.pdf
Drawing? Use interoperability of dx or gl with cuda or cl so drawing doesnt cross pci-e lane. Can even do raytracing at corners so no z-fighting anymore, even going pure raytraced screen is doable with mainstream gpu using a low depth limit.
Physics? The easiest part, just iterate a simple Euler or Verlet integration and frequently stability checks if order of error is big.
Map/terrain generation? You just need a Mersenne-twister and a triangulator.
Save game? Sure, you can compress the data parallelly before writing to a buffer. Then a scheduler writes that data piece by piece to HDD through DMA so no lag.
Recursion? Write your own stack algorithm using main vram, not local memory so other kernels can run in wavefronts and GPU occupation is better.
Too much integer needed? You can cast to a float then do 50-100 calcs using all cores then cast the result back to integer.
Too much branching? Compute both cases if they are simple, so every core is in line and finish in sync. If not, then you can just put a branch predictor of yourself so the next time, it predicts better than the hardware(could it be?) with your own genuine algorithm.
Too much memory needed? You can add another GPU to system and open DMA channel or a CF/SLI for faster communication.
Hardest part in my opinion is the object oriented design since it is very weird and hardware dependent to build pseudo objects in gpu. Objects should be represented in host(cpu) memory but they must be separated over many arrays in gpu to be efficient. Example objects in host memory: orc1xy_orc2xy_orc3xy. Example objects in gpu memory: orc1_x__orc2_x__ ... orc1_y__orc2_y__ ...
The answer has already been chosen 6 years ago but for those interested to the actual question, Shadertoy, a live-coding WebGL platform, recently added the "multipass" feature allowing preservation of state.
Here's a live demo of the Bricks game running on Gpu.
I don't care if it's already been
done, for me the thesis is more of an
opportunity to learn about things in
depth and to do substantial work on my
own.
Then your idea of what a thesis is is completely wrong. A thesis must be an original research. --> edit: I was thinking about a PhD thesis, not a master thesis ^_^
About your question, the GPU's instruction sets and capabilities are very specific to vector floating point operations. The game logic usually does little floating point, and much logic (branches and decision trees).
If you take a look to the CUDA wikipedia page you will see:
It uses a recursion-free,
function-pointer-free subset of the C
language
So forget about implementing any AI algorithms there, that are essentially recursive (like A* for pathfinding). Maybe you could simulate the recursion with stacks, but if it's not allowed explicitly it should be for a reason. Not having function pointers also limits somewhat the ability to use dispatch tables for handling the different actions depending on state of the game (you could use again chained if-else constructions, but something smells bad there).
Those limitations in the language reflect that the underlying HW is mostly thought to do streaming processing tasks. Of course there are workarounds (stacks, chained if-else), and you could theoretically implement almost any algorithm there, but they will probably make the performance suck a lot.
The other point is about handling the IO, as already mentioned up there, this is a task for the main CPU (because it is the one that executes the OS).
It is viable to do a masters thesis on a subject and with tools that you are, when you begin, unfamiliar. However, its a big chance to take!
Of course a masters thesis should be fun. But ultimately, its imperative that you pass with distinction and that might mean tackling a difficult subject that you have already mastered.
Equally important is your supervisor. Its imperative that you tackle some problem they show an interest in - that they are themselves familiar with - so that they can become interested in helping you get a great grade.
You've had lots of hobby time for scratching itches, you'll have lots more hobby time in the future too no doubt. But master thesis time is not the time for hobbies unfortunately.
Whilst GPUs today have got some immense computational power, they are, regardless of things like CUDA and OpenCL limited to a restricted set of uses, whereas the CPU is more suited towards computing general things, with extensions like SSE to speed up specific common tasks. If I'm not mistaken, some GPUs have the inability to do a division of two floating point integers in hardware. Certainly things have improved greatly compared to 5 years ago.
It'd be impossible to develop a game to run entirely in a GPU - it would need the CPU at some stage to execute something, however making a GPU perform more than just the graphics (and physics even) of a game would certainly be interesting, with the catch that game developers for PC have the biggest issue of having to contend with a variety of machine specification, and thus have to restrict themselves to incorporating backwards compatibility, complicating things. The architecture of a system will be a crucial issue - for example the Playstation 3 has the ability to do multi gigabytes a second of throughput between the CPU and RAM, GPU and Video RAM, however the CPU accessing GPU memory peaks out just past 12MiB/s.
The approach you may be looking for is called "GPGPU" for "General Purpose GPU". Good starting points may be:
http://en.wikipedia.org/wiki/GPGPU
http://gpgpu.org/
Rumors about spectacular successes in this approach have been around for a few years now, but I suspect that this will become everyday practice in a few years (unless CPU architectures change a lot, and make it obsolete).
The key here is parallelism: if you have a problem where you need a large number of parallel processing units. Thus, maybe neural networks or genetic algorithms may be a good range of problems to attack with the power of a GPU. Maybe also looking for vulnerabilities in cryptographic hashes (cracking the DES on a GPU would make a nice thesis, I imagine :)). But problems requiring high-speed serial processing don't seem so much suited for the GPU. So emulating a GameBoy may be out of scope. (But emulating a cluster of low-power machines might be considered.)
I would think a project dealing with a game architecture that targets multiple core CPUs and GPUs would be interesting. I think this is still an area where a lot of work is being done. In order to take advantage of current and future computer hardware, new game architectures are going to be needed. I went to GDC 2008 and there were ome talks related to this. Gamebryo had an interesting approach where they create threads for processing computations. You can designate the number of cores you want to use so that if you don't starve out other libraries that might be multi-core. I imagine the computations could be targeted to GPUs as well.
Other approaches included targeting different systems for different cores so that computations could be done in parallel. For instance, the first split a talk suggested was to put the renderer on its own core and the rest of the game on another. There are other more complex techniques but it all basically boils down to how do you get the data around to the different cores.