Sign in to follow this  
Lode

OpenGL Idea for a new engine

Recommended Posts

I find this very annoying of myself: I always make some cool engine for a game, but never acutally finish the game itself, ending up with nothing. Usually I also find the code of the game quite bad after I've left it alone for a while. Luckily each engine contributed something more to my main "library", so that making the next game always goes easier and better. Anyway, I've been working on a 2D tile engine for an RPG game, but now I was thinking, if I'd give every 2D tile a 3D shape instead and make the character walk around it in first person, and make every monster a 2D sprite (so that it's easy to draw lots of monsters without doing 3D modeling), wouldn't that be cool? But if I'd make such an engine, then everything would still be tile based, each tile would have a certain height and shape. I already have a tile engine, which saves tile worlds in sectors of 32x32 tiles, and which uses runlength encoding, so that when saving the map and many tiles have the same picture, it gets compressed. I'd use that same engine for the 3D world. Tiles would get a 3D shape, like ground, wall, pillar, floor+ceiling, statue, ... and a few textures that would be placed on predefined places on these shapes. Entering a house would be like this: you step in front of the door and get "teleported" to the inside of the house, which is in fact somewhere totally else (that's exactly how it works in my 2D tile engine). Say that the world would exist out of 1024x1024 such tiles (32x32 sectors of 32x32 tiles each), each tile in 3D would have on average 24 triangles (a simple ground square would be 4 triangles to allow fluent height differences, some more comples shapes would have more), then I'd have a world consisting out of 24 million triangles, plus monsters and trees in it that'd be sprites. What would be a good way to render such a world in realtime? I know modern 3D cards can render millions of triangles a second, but I'm not sure if the world structure I described above supports that? Do you think it would be possible to be standing somewhere high in this landscape and see with the camera a far view of all these 1024x1024 tiles at once? :) I'd be using OpenGL without extensions.

Share this post


Link to post
Share on other sites
Rendering it all at once might be pushing it :D Though the real problem might not be the triangles but the textures for everything. But due to your convenient format you can easily do culling by rendering, say, only nine sectors, or only the six sectors in front of the player.

Incidentally, Might & Magic (and probably quite a few others, but not quite so late) used this kind of "3D world with sprites" setup for a long time. It didn't harm the gameplay, but it was ugly beyond help, especially considering that by the time of number eight, it was already the year 2000.

Share this post


Link to post
Share on other sites
Other games like this (although they use geometry instead of sprites and the viewpoint might be a bit different) are shadowgrounds, neverwinter nights and warcraft 3, i even made a FPMS (first person mine sweeper) once using a similar technique.
So it's definitely possible, just make sure you don't end up with tons of different textures, a big texture atlas is probably the best way.
Then put all those tiles in a single VBO one after each other.
At this point it's pretty easy to just render all visible tiles.

Share this post


Link to post
Share on other sites
The basic concept sounds like the original Wolfenstein 3D game. You should see about playing that and seeing if it gives any ideas. Keep in mind that Wolfenstein is Very old, and was shortly surpassed by better things like Doom, even before the advent of OpenGl and hardware rendering.


Quote:
Original post by Lode
Do you think it would be possible to be standing somewhere high in this landscape and see with the camera a far view of all these 1024x1024 tiles at once? :)

This last part sounds a little bit different though; Wolfenstein was an indoors dungeon style game. Where you have walls that pretty much keep you from seeing too much at once.
What you describe about seeing the landscape; sounds more suited to a heightfield type terrain; one of these would be a better use of triangles if you're going to be outdoors. And they have their own set of algorithms for managing them. So check those out as well, its a well covered topic.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

Sign in to follow this  

  • Announcements

  • Forum Statistics

    • Total Topics
      628375
    • Total Posts
      2982310
  • Similar Content

    • By test opty
      Hi all,
       
      I'm starting OpenGL using a tut on the Web. But at this point I would like to know the primitives needed for creating a window using OpenGL. So on Windows and using MS VS 2017, what is the simplest code required to render a window with the title of "First Rectangle", please?
       
       
    • By DejayHextrix
      Hi, New here. 
      I need some help. My fiance and I like to play this mobile game online that goes by real time. Her and I are always working but when we have free time we like to play this game. We don't always got time throughout the day to Queue Buildings, troops, Upgrades....etc.... 
      I was told to look into DLL Injection and OpenGL/DirectX Hooking. Is this true? Is this what I need to learn? 
      How do I read the Android files, or modify the files, or get the in-game tags/variables for the game I want? 
      Any assistance on this would be most appreciated. I been everywhere and seems no one knows or is to lazy to help me out. It would be nice to have assistance for once. I don't know what I need to learn. 
      So links of topics I need to learn within the comment section would be SOOOOO.....Helpful. Anything to just get me started. 
      Thanks, 
      Dejay Hextrix 
    • By mellinoe
      Hi all,
      First time poster here, although I've been reading posts here for quite a while. This place has been invaluable for learning graphics programming -- thanks for a great resource!
      Right now, I'm working on a graphics abstraction layer for .NET which supports D3D11, Vulkan, and OpenGL at the moment. I have implemented most of my planned features already, and things are working well. Some remaining features that I am planning are Compute Shaders, and some flavor of read-write shader resources. At the moment, my shaders can just get simple read-only access to a uniform (or constant) buffer, a texture, or a sampler. Unfortunately, I'm having a tough time grasping the distinctions between all of the different kinds of read-write resources that are available. In D3D alone, there seem to be 5 or 6 different kinds of resources with similar but different characteristics. On top of that, I get the impression that some of them are more or less "obsoleted" by the newer kinds, and don't have much of a place in modern code. There seem to be a few pivots:
      The data source/destination (buffer or texture) Read-write or read-only Structured or unstructured (?) Ordered vs unordered (?) These are just my observations based on a lot of MSDN and OpenGL doc reading. For my library, I'm not interested in exposing every possibility to the user -- just trying to find a good "middle-ground" that can be represented cleanly across API's which is good enough for common scenarios.
      Can anyone give a sort of "overview" of the different options, and perhaps compare/contrast the concepts between Direct3D, OpenGL, and Vulkan? I'd also be very interested in hearing how other folks have abstracted these concepts in their libraries.
    • By aejt
      I recently started getting into graphics programming (2nd try, first try was many years ago) and I'm working on a 3d rendering engine which I hope to be able to make a 3D game with sooner or later. I have plenty of C++ experience, but not a lot when it comes to graphics, and while it's definitely going much better this time, I'm having trouble figuring out how assets are usually handled by engines.
      I'm not having trouble with handling the GPU resources, but more so with how the resources should be defined and used in the system (materials, models, etc).
      This is my plan now, I've implemented most of it except for the XML parts and factories and those are the ones I'm not sure of at all:
      I have these classes:
      For GPU resources:
      Geometry: holds and manages everything needed to render a geometry: VAO, VBO, EBO. Texture: holds and manages a texture which is loaded into the GPU. Shader: holds and manages a shader which is loaded into the GPU. For assets relying on GPU resources:
      Material: holds a shader resource, multiple texture resources, as well as uniform settings. Mesh: holds a geometry and a material. Model: holds multiple meshes, possibly in a tree structure to more easily support skinning later on? For handling GPU resources:
      ResourceCache<T>: T can be any resource loaded into the GPU. It owns these resources and only hands out handles to them on request (currently string identifiers are used when requesting handles, but all resources are stored in a vector and each handle only contains resource's index in that vector) Resource<T>: The handles given out from ResourceCache. The handles are reference counted and to get the underlying resource you simply deference like with pointers (*handle).  
      And my plan is to define everything into these XML documents to abstract away files:
      Resources.xml for ref-counted GPU resources (geometry, shaders, textures) Resources are assigned names/ids and resource files, and possibly some attributes (what vertex attributes does this geometry have? what vertex attributes does this shader expect? what uniforms does this shader use? and so on) Are reference counted using ResourceCache<T> Assets.xml for assets using the GPU resources (materials, meshes, models) Assets are not reference counted, but they hold handles to ref-counted resources. References the resources defined in Resources.xml by names/ids. The XMLs are loaded into some structure in memory which is then used for loading the resources/assets using factory classes:
      Factory classes for resources:
      For example, a texture factory could contain the texture definitions from the XML containing data about textures in the game, as well as a cache containing all loaded textures. This means it has mappings from each name/id to a file and when asked to load a texture with a name/id, it can look up its path and use a "BinaryLoader" to either load the file and create the resource directly, or asynchronously load the file's data into a queue which then can be read from later to create the resources synchronously in the GL context. These factories only return handles.
      Factory classes for assets:
      Much like for resources, these classes contain the definitions for the assets they can load. For example, with the definition the MaterialFactory will know which shader, textures and possibly uniform a certain material has, and with the help of TextureFactory and ShaderFactory, it can retrieve handles to the resources it needs (Shader + Textures), setup itself from XML data (uniform values), and return a created instance of requested material. These factories return actual instances, not handles (but the instances contain handles).
       
       
      Is this a good or commonly used approach? Is this going to bite me in the ass later on? Are there other more preferable approaches? Is this outside of the scope of a 3d renderer and should be on the engine side? I'd love to receive and kind of advice or suggestions!
      Thanks!
    • By nedondev
      I 'm learning how to create game by using opengl with c/c++ coding, so here is my fist game. In video description also have game contain in Dropbox. May be I will make it better in future.
      Thanks.
  • Popular Now