So now i'm working in ogre, trying to make a game.
But my question is quite simple.
When Ogre loads a file, it then puts it in an so called Entity objects.
I had an idea where i would load all my resources in Ogre, and then serialise them,
and store it all in one file, so i could later just load them as binary code in the
actual game.
My question is if this method would be faster than always loading
the actual files.
I do mention that i work in scenes, so that not ALL of the resources are
loaded in at once ofcourse.
Thanks for your help.
Games often have own resource system. Instead of loading individual files (jpg textures, png images, mp3 files, ogg files, meshes) they pack all of those data into some "smart" file. It is a middle layer.
1. orginal files (models, textures, entities) -> pack into "game_resource_file"
2. load "game_resource_file" in game
Answer to the question: yes it should make loading faster.
But there are some flaws: as you see you need at least two steps to have a resource in your game. When you change one texture (out of 100) it can take long time before you can see it on the screen. You have to take that texture, rebuild your resource file and then load in the game. Without that you simply load a changed texture in the game directly.
This resource pipeline problem is very important and can save (or add) large amount of development time.
Related
Im playing around with SFML and C++ and have one question, when loading a texture, you must specify its directory like so:
sf::Texture myTexture;
if(!(myTexture.loadFromFile("C:\\Folder\\image.png")));
But when distributing my game how will i be sure that the user will download the game onto the same drive, and image.png may be on the E: drive instead of the C: drive. I want to know a way to locate an image file in C++ without having to specif its directory. Here is theoretical code
if(!(myTexture.loadFromFile(#"image.png")));
so now no matter where this image is located my game can find the image. My only concern is that someone might already have a file called image.png on there computer so for this i would give the image files very abstract and unique names, to prevent duplication.
Loading images (and sounds, fonts etc) from a relative path works as well.
If you are concerned about potential filename collisions, distribute your game with a folder containing all your assets. For example yourGame_resources, placed at the same level as your executable. Load by
myTexture.loadFromFile("yourGame_resources/image.png")
I'm just curious if there is a way to use OpenGL to write pixel data to an external JPEG/PNG/some other image file type (and also create an image to write the data to if one does not already exist). I couldn't really find anything on the subject. My program doesn't really make use of openGL at all otherwise, I just need something that can write out images.
Every image "put into" or "taken from" OpenGL is in a rather raw pixel format. OpenGL does neither have functionality for file I/O nor for handling of sophisticated image formats like e.g. BMP, JPEG or PNG, as that is completely out of its scope. So you will have to look for a different library to manage that and if this was the only reason you considered OpenGL, then you don't need it at all.
A very simple and easy to use one (and with an interface similar to OpenGL) would be DevIL. But many other larger frameworks for more complex tasks, like Qt (GUI and OS) or OpenCV (image processing) have functionality for image loading and saving. And last but not least many of the individual formats, like JPEG or PNG usually also have small official open-source libraries for handling their respective files.
Currently I have a 3D Cube that I drew by writing coordinates, that can rotate and move on a black screen.
Now I have a Model that I created in "3Ds Max"(It's a little backyard with high stonewalls, so I'm trying to use it as my world object.) and I want to load this model into my DirectX9/C++ project.
As far as I see in DirectX SDK examples this code is for loading .X model (which needs a plugin for "3Ds Max" to export that kind of extension. I'm not sure of this.)
Code for loading .X files into DX9/C++:
D3DXLoadMeshFromX( "Tiger.x", D3DXMESH_SYSTEMMEM,
g_pd3dDevice, NULL, &pD3DXMtrlBuffer, NULL,
&g_dwNumMaterials, &g_pMesh )
Is there a function like "D3DXLoadMeshFromOBJ(.....)" to load an Object? How do I load and render .OBJ files? 8(
Another question of mine is what is the difference between an .X file and an .OBJ file and which of them should I use?
AFAIK, DirectX does not support wavefront object files out of the box. You will need an external mesh loader for that purpose.
I can remember, that in the DX 10 SDK is a sample of how to load an .obj file, I think the sample is called MeshFromOBJ10. I don't know if it is of any use in DirectX 9.
As far as I know, the standard .x just supports basic meshes with no enhancements such as animation. If you want to try out graphical programming it is not bad, but if you are aiming for higher concepts you can later switch. I guess you can look up the advantages of the .obj files here.
It is always a good idea to create an abstraction for the input data you are using. For example, you could create a class AbstractMesh and an implementation XMesh deriving from it. Later on, you can than add other implementations like OBJMesh or anything similar.
I hope I could help you a bit :) Happy Coding!
Animation is full supported in x file format, and furthermore, it support fx files when you want to use shaders. A exporter plugin and samples you can download from this page:
http://www.cgdev.net/download.php
Here's the issue: I'm developing some Flash web sites and really enjoying AS3.
The problem: PNG 24-bit images are too big... I have three PNG images with transparency that I'd like to rotate through on the "Home page" every 10 seconds or so. Great. No problem - but instead of embedding all three PNGs in the SWF, which would take the thing longer to load, I'd like to load them dynamically from external files, so that the user doesn't have to wait around for images to load that aren't going to be displayed for another 10-15 seconds anyway. That's fine... I have working code for that.
The real problem: These PNG sizes, even loaded from external files on the fly, are really bugging me. One image is 350k when saved with Photoshop - 300k when I use PNGOUT. But... when I import the PNG into Flash's Library, I can go in and set it to JPG/Image Compression which reduces the size to about 45k, yet maintains the alpha information!! If Flash can compress my PNG that much, and still make it look good, why can't I find an app that can do the same for an external file? I'd be content to load my images into the Flash library and let it handle the compression, but if I end up with 5 or 6 images, that still turns out to be too long of a loading time.
Summary: How can I shrink my 350k PNG image with transparency down to 45k like Flash does when I import it into it's library?
Possible solution: Or.... hmmmm.... this could be a workaround... maybe I could just make a separate SWF movie for each PNG I want to use which uses the Flash compressed image - then read that file dynamically using a Loader... That ought to work! I shall return and report...
But still, how does Flash compress those PNGs so much more than compressors like PNGOUT? Maybe I'm just not passing in the right parameters for them to be effective.
Thanks for reading my ramblings. You all are a great sounding board!
PNG compression is lossless, so it can't compete with lossy perceptual compression schemes as JPEG. Just be sure that your png are the size to be displayed (or not : one trivial "compression" scheme would be to save your image scaled down and zoom it when displaying, but this is normally unsatisfactory). If you can't go below 24-bits (you cant go to a 256-pallete, I guesss) I dont think much can be done. I can only suggest to give a look at PngCrush.
I used to have the same question, but later, I think flash used JPEG compress for PNG files. The JPEG-compressed "png" is actually a variant that standard png format does not support, but flash supports. In my own flash project, I used it a lot. I even used swftools to generate an animated SWF from a lot of png, so I can load the single "png gallery" swf and use all the pngs inside.
I know that the question is a year old, but I thought it would be good for future reference. Using any of the png compression tools (PngCrush, Optipng) will not get anywhere near the same results as Flash compression.
The best way I've found to use flash compression without creating each swf in the Flash IDE is using SwfTools' png2swf utility, it will keep alpha channels and also allow you to set the jpeg's compression quality.
http://www.swftools.org/png2swf.html
I am trying to develop a 3D game in openGL and i need to create many 3D objects.. I am a begginner in openGL.. I have tried with many 3D softwares like Blender , MODO, Unity 3D and Cheetah.
I am easily able to create my objects with these and exporting as Wavefront .OBJ, and converting it to a header file using a perl script. This header file is added to my openGL project..
The 3D objects are seen, but its not perfect. The script i used is to convert the .OBJ to .h using TRIANGLES.. And the object is seen with triangles. Its not full.. No way when i used TRIANGLE STRIP,FAN..? Problems with the vertices..
Is the problem with my Script or is it the wrong way i have gone..?? Or is there any other best ways to directly import 3D objects to openGL..??
The below link is the best one which you can get for 3D objects to openGL.. i got the scripts from these..
http://www.heikobehrens.net/2009/08/27/obj2opengl/
please help..
You don't want to go that way. Direct drawing mode (using TRIANGLE and friends) is extremely slow in OpenGL.
Instead, you should pick a decent format and write a loader for it (or use one found on the web). Good formats would be 3ds, obj if gzipped, collada.
Here's an example tutorial on loading from Milkshape files.
Once you load your objects programatically, you can use Vertex Arrays, or even better VBO's to display them. This is waaay faster.
Google for a mesh loader for your favorite format, or write one yourself.
I have written a reader/renderer for AC3D files that works fine on the iPhone (OpenGL ES)
Feel free to have a look at it here.
There is also an obj loader by Jeff Lamarche at google code.
AC3D can reduce the triangle count pretty good and as an alternative I ported QVis to the mac. My reader/renderer also tries to build tri-strips.
About VBO's. I have not seen any gained performance when using them in the iPhone. I'm not the only one.