XNA using C#

[Cloud9_]

Originally Posted by Froofy-D

Not sure if you guys working on RPG games have noticed, but they have an RPG Starter Kit up on XNA.com:

XNA Creators Club Online - role-playing game

Seems pretty nice. If nothing else you could at least get some art assets out of it and see how they do some stuff.

Yeah i nabbed the art from it I took some things from it, portals and quest structure mostly. I like what they did though

[Froofy-D]

I wouldn't mind seeing your updated version with new art Cloud.

I have an update worth posting I guess. I have some decent AI going. There are 3 factions, Pirate, Aliens, and NPCs. Pirates and Aliens hate everyone. NPCs like you but hate Pirates and Aliens. Below is a picture of me training a bunch of Aliens to the guards. I also have a simple UI going with portraits and a Radar. Radar is bottom right. Enemies = red, friendly = blue, neutral = yellow. You can't "die" yet, but if your hull goes to 0 there will be a super big explosion.

Also, not sure if you already know this, but before you draw SpriteFonts you have to cast their positions to integers. I wasn't doing that so the font was slightly blurry. Now the nameplates, UI, and floating damage text are crisp.

DL of the source: SinglePlayerDemo.zip

Change the resolution in SinglePlayerDemo.cs on this line:

// set graphics mode
InitGraphicsMode(1280, 800, false);

Put true for fullscreen. XNA looks decent in 3D even with some simple models and the default BasicEffect shader. Oh and the green grid is just for debugging, isn't supposed to be there.

[KiL4H]

Dunno who said what, but I've worked around 1 year with XNA(not 2.0) on a medical project and my personal opinion: It is sometimes even harder to use than opengl/directx.

Of course this always depends on what are you doing exactly. From a learning phase point of view it has several tools that can make anyones life easier, but I personally found it quite annoying most of the times on specific works. It reminds me older version of Directx and their annoying buffers. It is too strict following GPU implementation without even considering other options (an example: you cannot retrieve information from the depth buffer in GPU, GPU do not support it but you may want it sometimes,etc).

If you aren't asked for a .NET/XNA special support, I don't suggest you work with it unless, of course, they improved it.

[Hachima]

I never worked with XNA 1.0 but I have done some things with 2.0. Done a few 2D and 3D games. Does DirectX/OpenGL come with all the Matrix/Vector manipulation stuff built in too? For rotating/transforming models etc?

I know that XNA 2.0 is different enough than 1.0 that 1.0 projects won't compile under 2.0 without some changes. I've liked using XNA but I've never dealt with DirectX before.

This seemed to be a good comparison for disadvantages of XNA though.

Well when you're specifically talking about the 360, the main disadvantage compared to having a real dev-kit is that you don't have full low-level access to machine's capabilities, and instead have to go through a managed API. This brings the following problems:

This seems to be a good post on disadvantages of XNA

-You can't manually manage memory. On the PC this is hardly a big deal at all (since even in native code you're working with virtual memory anyway), but on the 360 it's a different story. You have a very very limited set of memory to work from, and if you're looking to make full-scale commercial-level games you will probably come up against the limits pretty quickly. For smaller games it shouldn't be a problem.

-You have to work with .NET CF's garbage collector. Whether you love working with one or not on PC, on the 360 the situation is once again different because GC compactions can cause some serious latency. You have to be careful and forward-thinking with how you handle your data to avoid this (for example, using structs and making sure they don't get auto-boxed).

-No access to Xenon's (360 CPU) vector unit. Because of this your floating-point abilities are limited compared to many PC CPU's, or what commercial devs can achieve.

-No native access to Xenos (360 GPU). You're essentially limited to what you can pull off in D3D9, so that XNA is consistent for both the PC and the 360. This means you can't work with native command buffers, read from the GPU's z-buffer, manually manage tiling, or use MEMEXPORT. Also the biggest problem, IMO, is that you can't use the special FP10 back-buffer format. This is a special 32-bpp format that allows you to use floating-point components while still maintaining a small footprint for your back-buffer (which is important since a larger back-buffer means more tiles are needed in order to fit in the 10MB of eDRAM). Without this you have to either use A16R16G16B16F (which has twice the footprint and doesn't support HW blending) or some custom color-space in A8R8G8B8 (requires special shader math which adds complexity, also can't be alpha-blended).

-You can't sell your game, unless you find a publisher or somehow get MS to publish it for you.

[Fog]

Wow -- how reputable is the source of that post? I've never developed on the 360, but I am familiar with some C# internals, and the garbage collector should definitely not be taking up enough cycles that you should be concerned about it, unless you are doing something extremely mysterious, or writing really bad code.

That's on a PC, mind you, but it's not like the 360's specs are that bad, are they? I don't understand why it would suddenly be a problem. Ditto for memory allocation. At worst, if you really, really need to manage your own memory for some resource-intensive bottleneck routine, can't you write unsafe code? (For the audience, in C#, the "unsafe" keyword on a method or class lets you use pointers for direct memory access, whereas that's normally not kosher in .NET.)

Like I said, I don't know anything about the 360, so maybe I can believe that memory usage is a bigger deal than I'd expect, but garbage collection? Really?

[Hachima]

I was mainly backing up what KiL4H was saying about having less access to some stuff closer to the hardware.

the 360 uses a GC more like the GC in CF.Net which is a bit different than regular .NET I believe

.NET Compact Framework Team : Managed Code Performance on Xbox 360 for XNA: Part 2 - GC and Tools

has a good explanation with more links that describe more about what goes on.

[Fog]

Originally Posted by Hachima

I was mainly backing up what KiL4H was saying about having less access to some stuff closer to the hardware.

the 360 uses a GC more like the GC in CF.Net which is a bit different than regular .NET I believe

.NET Compact Framework Team : Managed Code Performance on Xbox 360 for XNA: Part 2 - GC and Tools

has a good explanation with more links that describe more about what goes on.

Aha -- I wasn't thinking about the necessity to really keep a steady rate of processing going in the background, since in most games you have to churn out 30 frames per second pretty much forever. I understand how the intermittent garbage collection could be a problem then.

Thanks for the link!

[Froofy-D]

Like many programming language features, GC can be both a bonus and a liability.

From experience, there are many programmers even in the professional world, that shouldn't be allowed to manage memory (think of every game you've heard of that has memory leaks). But then, if you never get experience managing memory you may have bad habits when it comes to GC languages.

The best thing you can do in either case (GC or not) is to re-use memory. Barring a seamless world environment, even in C++, I consider any memory allocation that isn't during level loading a bug. Additionally, any use of pointers that is not absolutely required is also a bug.

[Kharza-kzad]

I haven't done much on my xna stuff, work has been killing me, but I got back into it this weekend and found something cool.

It looks like now there's a way to get stuff out of the poser world and into your game. I grabbed the daz studio freebie thing (which is like a poser light) and was able to get an animation exported and converted into fbx.

I have no idea what poser stuff is legal to use in a game, but I bought some of the daz figures and stuff and will be using them for the time being. They look really really nice, and have so many tweakable dials that you can create a ton of different looking characters.

They are way too high res though. Going to have to spend some time optimizing them.

[Zuuljin]

I know its been almost 2 months since this post, but I've been doing a bit of XNA stuff and just wanted to respond to this:

-You can't manually manage memory. On the PC this is hardly a big deal at all (since even in native code you're working with virtual memory anyway), but on the 360 it's a different story. You have a very very limited set of memory to work from, and if you're looking to make full-scale commercial-level games you will probably come up against the limits pretty quickly. For smaller games it shouldn't be a problem.

-You have to work with .NET CF's garbage collector. Whether you love working with one or not on PC, on the 360 the situation is once again different because GC compaction's can cause some serious latency. You have to be careful and forward-thinking with how you handle your data to avoid this (for example, using structs and making sure they don't get auto-boxed).

-No access to Xenon's (360 CPU) vector unit. Because of this your floating-point abilities are limited compared to many PC CPU's, or what commercial devs can achieve.

-No native access to Xenos (360 GPU). You're essentially limited to what you can pull off in D3D9, so that XNA is consistent for both the PC and the 360. This means you can't work with native command buffers, read from the GPU's z-buffer, manually manage tiling, or use MEMEXPORT. Also the biggest problem, IMO, is that you can't use the special FP10 back-buffer format. This is a special 32-bpp format that allows you to use floating-point components while still maintaining a small footprint for your back-buffer (which is important since a larger back-buffer means more tiles are needed in order to fit in the 10MB of eDRAM). Without this you have to either use A16R16G16B16F (which has twice the footprint and doesn't support HW blending) or some custom color-space in A8R8G8B8 (requires special shader math which adds complexity, also can't be alpha-blended).

-You can't sell your game, unless you find a publisher or somehow get MS to publish it for you.

Since this, I believe that the XNA creators club has launched, with a plethora of documentation, tutorials and information about XNA. I dont think XNA is for the multi-million dollar game companies, or that you should be making the next GTA game or Crysis. Its meant to be very easy to pick up, so anyone with basic programming knowledge, or anyone who is interested in learning it, can do so and make some simple and (hopefully) fun games. Its meant for the hobbists.

You dont need direct hardware access to make a simple 2d sidescroller or a small 3d shooter. Nor should the GC make that big a difference in your game. Also, this framework is fairly new. Perhaps in later iterations they will add more optimizations and support for more direct access.

The last point on that list is also false. Once the XNA thing goes live during the holidays, your game (if approved) will be put up on LIVE for purchase, and you get a cut of the sales. That sounds like a great marketing plan to me.

[Kasi]

I am having an issue here that I hope someone out there can help me with. I have a .X file of a spaceship I want to use in my XNA program. (similar in ways to Froofy I am working on a 3d space game, but like Cloud its more to expand my knowledge. Well I also want to make a cool game with several features I'm interested in.)

The problem is relative texture paths. This is the model I am using.

3D 3ds Capital Ship Space

I really like the look of it since I plan to make my game more about controlling a larger ship, not a fighter. So to get back to the issue with relative paths. When I import that into my XNA project I get this.

Error 1 Missing asset "D:\TDModels\FinalCapital\HullR.bmp".

I have tried a couple different 3d programs, and if I had 3d studio max I think i could fix it, but every time I go and use XSI Mod or blender to load that model and then move it to fbx or x format either the texture stuff gets all messed up or the model doesn't even load. One day I would like to know more about 3d graphics suites programs, but for right now I just want to be able to use that damn model in my game. Thanks for any help.

[Froofy-D]

Originally Posted by Kasi

I am having an issue here that I hope someone out there can help me with. I have a .X file of a spaceship I want to use in my XNA program. (similar in ways to Froofy I am working on a 3d space game, but like Cloud its more to expand my knowledge. Well I also want to make a cool game with several features I'm interested in.)

The problem is relative texture paths. This is the model I am using.

3D 3ds Capital Ship Space

I really like the look of it since I plan to make my game more about controlling a larger ship, not a fighter. So to get back to the issue with relative paths. When I import that into my XNA project I get this.

Error 1 Missing asset "D:\TDModels\FinalCapital\HullR.bmp".

I have tried a couple different 3d programs, and if I had 3d studio max I think i could fix it, but every time I go and use XSI Mod or blender to load that model and then move it to fbx or x format either the texture stuff gets all messed up or the model doesn't even load. One day I would like to know more about 3d graphics suites programs, but for right now I just want to be able to use that damn model in my game. Thanks for any help.

Is that the folder where you are storing your projrect? If it isn't, you can open the .X file in C# or Notepad and hand-edit the texture paths without bothering with a 3D model program. Screenshot below of how my project is setup and an example model.

- all models are in Content/Models
- all textures in Content/Textures
- all paths are defined relative "//Textures//texture.bmp" and not absolute "C://Program Files/ etc.... "

Sometimes model creators leave absolute paths in the model files by accident causing them to throw errors like you are seeing. Editing them with a text editor should work.

If you have no luck, PM me, mail me the model, and I'll set it up to work in XNA, and send it to you. Looks pretty cool I wouldnt mind playing with it as well.

[Kasi]

The problem I seem to be having is the file is in binary mode and I can't figure out how to get it into ascii. I know it should be as simple as using a text editor, but when I tried doing it I just got errors. Is there a free editor you would recommend?

[Froofy-D]

Oh that sucks. Can't recommend anything personally. I tried using some XSI and 3DSMax .x file plugins, but they all messed up the models. I had to edit mine by hand.

You might try the TurboSquid Tentacles program:

Turbo Squid -- Tentacles

If you bought that, you might ask for a refund or make them give you a .txt version of the file. It won't be useful for anything if you cannot edit the file paths.

[Cloud9_]

Is there a way to render the model without the texture? Not like you need a texture to learn whatever you want to learn... unless you're writing a shader or something where the texture could be useful