I am writing a very simple 3d particle software rendering system, but I am only really interested in coding the particle system and the rasterizer, so what I am looking for, is the easiest way to go from 3d particle coordinates, through camera, to screen coordinates, but with features like variable FOV, and targeted (look at) camera.
Any additional features such as distance from point to point, bounding volumes etc. would be a bonus, but ease of use is more important to me than features.
The only license requirement is that it's free (as in beer).
You probably want a scenegraph library. Many C++ scene graph libraries exist. OpenScenegraph is popular, Coin3D (free for non-commercial use) is an implementation of the OpenInventor spec, any of them would probably fit your need as it doesn't sound like you need any cutting-edge support. There is also Panda3D, which I've heard is good if you're into Python.
You could do all of this in a straight low-level toolkit like OpenGL but without prior experience it takes a lot longer to get a handle on using OpenGL than any of the scenegraph libraries.
When choosing a scenegraph library it will probably just come down to personal preference as to which API you prefer.
Viewing is done with elementary transformations, the same way that model transformations are done. If you want some convenience functions like gluLookAt() in GLU, then I don't know, but it would be really easy to make your own.
If you do want to make your own Look At function etc. then I can recommend eigen which is a really easy to use linear algebra library for C++.
If you're trying to just focus on the rendering portion of a particle system, I'd go with an established 3D rendering library.
Given your description, you could consider trying to just add your particle rasterization to one or both of the software renderers in Irrlicht. One other advantage of this would be that you could compare your results to the DX/OGL particle effect renderers that already exist. All of the plumbing/camera management/etc would be done for you.
You may also want to have a look at the Armadillo C++ library
Related
I know GLUT's quadrics, I used it in a few programs when I was in school. Now I'm working on a real world application and I find myself in need of drawing some geometric primitives (cubes, spheres, cylinders), but now I also know that GLUT is a no longer supported and it's last update was in like 2005. So I'm wondering if there's anything other than GLUT's quadrics to draw such geometric shapes. I'm asking if there's anything made before I go ahead and start making my own from vertices arrays.
Yes, you can! You can use the native API of the OS to create a window with OpenGL capabilities.
The advantage of GLUT is that is makes this task easier and is a cross-platform solution.
There are other cross-platform libraries that are more complex to work with but provide the same functionality, like Qt.
NeHe has a huge amount of examples that use several different technologies to accomplish what you are looking for. Check the bottom of the page.
Here is a demo for Windows that creates a window and draws a simple OpenGL triangle inside it. This demo removes all the window frame to give the impression that a triangle is floating on the screen. And here is a similar demo for Linux.
GLUT is just some conveniece framework that came to life way after OpenGL. The problem is not, that GLUT is unmaintained. The problem is, that GLUT was not and never will be meant for serious applications.
Then there's also GLU providing some primitives, but just as GLUT it's merely a companion library. You don't need either.
The way OpenGL works is, that you deliver it arrays of vertex attributes (position, color, normal, texture coordinates, etc.) and tell to draw a set of primitives (points, lines, triangles) from those attributes from a second array of indices referencing into the vertex attribute arrays.
There used to be the immediate mode in versions prior to OpenGL-3 core, but that got depreceated – good riddance. It's only use was for populating display lists which used to have a slight performance advantage if one was using indirect GLX. With VBOs (server (=GPU) side vertex attribute storage) that's no longer an issue.
While GLUT has not been maintained, FreeGLUT has. There are still several alternatives though.
GLFW is a cross-platform windowing system which is easy to get up and running, and also provides the programmer with control of the main application loop.
SFML has support for many languages and also integration capabilities with other windowing schemes, in addition to being cross-platform.
Finally, Qt is another, popular, cross-platform windowing framework.
Now I'm working on a real world application and I find myself in need of drawing some geometric primitives (cubes, spheres, cylinders),
Actually, I don't remember anything except glut that would provide generic primitives. This might have something to do with the fact that those generic primitives are very easy to implement from scratch.
You can use other libraries (libsdl, for example, or Qt) to initialize OpenGL, though.
Most likely if you find generic library for loading meshes (or anything that provides "Mesh" object), then it will have primtives.
is a no longer supported and it's last update was in like 2005
Contrary to popular belief, code doesn't rot and it doesn't get worse with time. No matter how many years ago it was written, if it still works, you can use it.
Also there is FreeGLUT project. Last update: 2012.
I've spent quite some time searching a simple / fast c++ library (Win / Linux) that can answer the two questions 'does this ray crosses any of the triangles?' or 'where is the first intersection, if there are any?'.
It's for my little game I'm writing and will be used to see if a NPC can see a player and also to check if a player can fall all the way to the ground (or not).
The triangles will not move (well, if you can flag a triangle group 'on' / 'off' that would be nice).
I actually found some libraries but only non-continued (or it seems) like OZCollide for example.
Of course there are all those new shiny Physics engines out there but I don't need 99% of what they offer.
A bonus would be if the library can load .3ds an .b3d files and even better if it can be used in a multi threaded environment (creating several instances of the search data).
Thanks all!
Bullet Physics (http://bulletphysics.org/) is a physics library, but it's built in several layers.
Because of this it can be used as just a collision library which is quite efficient at casting rays through a scene.
(You wouldn't be using or be bothered by any of its physics features)
It's available on Windows and Linux, but also on several more platforms and even on game consoles.
The library is proven and used professionally by various game developers.
It does not directly support .3ds files, but it does has a pipeline for getting geometry from various 3D modelling applications converted to the right format Bullet understands.
It might feel overkill to use it because it's a physics library. But that is actually the reason you should be using it.
A physics library is highly reliant on a good collision library, which actually forces the collision library to be of high quality and offer excellent performance.
Well, there seems to be no 'simple & small' library / code out there so I guess the answer might be 'roll your own'.
That is what I did anyway:
a tool that uses Irrlicht to load up my (static) geometry and then save off all (triangle/vertex) data to a file, just 9 floats for each triangle.
Then a collision library that loads up the data into an octree and the c2005 triangle / ray intersection test and it works OK.
I am doing a scientific project in C++ and I need to draw simple animated 3-d images of moving atomic groups. What is a good and convenient graphics library to do that? Some general remarks are also appreciated. I work in Linux.
Thank you in advance, Roman
OpenGL of course,
one library you could use is glut for that.
have a look on http://nehe.gamedev.net/
If you want to show 3D in linux, you should use OpenGL. But since it is a C library, you can use a wrapper, like for example glt or sfml
The easiest library to use is Vtk. A more difficult and slower, but potentially better rasterization can be achieved using POVRAY.
I suggest looking at game oriented graphics engines. They provide OO wrappers around openGL and have lots of utility functions for loading 3d model formats etc.
If you don't want to get bogged down in writing the graphics, a game oriented renderer is likely the fastest way for you to get stuff on screen.
Ogre may be a good choice - it has a fairly large and helpful community.
Irrlicht is another possibility.
There are several possibilities, some perhaps more suitable than others, obviously!
I think any one of the options mentioned above would serve to do so.
I personally recommend OSG.
http://www.openscenegraph.org/projects/osg
I'm quite new to the whole field of GIS, and I'm about to make a small program that essentially overlays GPS tracks on a map together with some other annotations. I primarily need to allow scanned (thus raster) maps (although it would be nice to support proper map formats and something like OpenStreetmap in the long run).
My first exploratory program uses Qt's graphics view framework and overlays the GPS points by simply projecting them onto the tangent plane to the WGS84 ellipsoid at a calibration point. This gives half-decent accuracy, and actually looks good. But then I started wondering. To get the accuracy I need (i.e. remove the "half" in "half-decent"), I have to correct for the map projection. While the math is not a problem in itself, supporting many map projection feels like needless work. Even though a few projections would probably be enough, I started thinking about just using something like the PROJ.4 library to do my projections. But then, why not take it all the way? Perhaps I might aswell use a full-blown map library such as Mapnik (edit: Quantum GIS also looks very nice), which will probably pay off when I start to want even more fancy annotations or some other symptom of featuritis.
So, finally, to the question: What would you do? Would you use a full-blown map library? If so, which one? Again, it's important that it supports using (and zooming in and out with) raster maps and has pretty overlay features. Or would you just keep it simple, and go with Qt's own graphics view framework together with something like PROJ.4 to handle the map projections? I appreciate any feedback!
Some technicalities: I'm writing in C++ with a Qt-based GUI, so I'd prefer something that plays relatively nicely with those. Also, the library must be free software (as in FOSS), and at least decently cross-platform (GNU/Linux, Windows and Mac, at least).
Edit: OK, it seems I didn't do quite enough research before asking this question. Both Quantum GIS and Mapnik seem very well suited for my purpose. The former especially so since it's based on Qt.
See GDAL www.gdal.org for a solid background library for raster formats and manipulation, and it incorporates PROJ.4 for transformations.
QGIS relies on GDAL for some data import, amongst other things.
I'm looking for a free to use game engine math library. Specifically I'd like a good matrix and vector implementation. And everything needed to move objects in 3D space. Does anyone know any good ones? I'm targeting OpenGL. I'd like to write them myself but don't have the time.
I'd recommend OpenGL Mathematics (GLM)
Though if you want physics with your math you could go with Bullet Physics Library
Finally if you want an entire engine i'd go with OGRE
You might want to consider Blitz++.
Besides Ogre 3D, there's also Crystal Space. Here's an article that compares the two.
If you want an entire 3D engine (which of course would contain the 3d maths you need) see Ogre 3D (LGPL)
Take a look here
https://sourceforge.net/projects/mg3d/
It is an opensource engine that has all former OpenGL transformation routines. The implementation here is very straightforward and clear. And it is very easy to include the module with the routines in your project.
I have good work with Open Dynamics Engine is Full and Stable Physics Engine,
the ode in a BSD License, and have some functions for Matrix Manipulation, Quaternion and rotations.