10 replies to this topic

[Math]

Hi all,
I'm currently trying to find a 3D engine for my project.
I have a project that deals with managing a room in which objects are placed (table, chair, ...). We need to simulate and to model the propagation of a specific light source and we'll use our own algorithm for the diffusion.
In the scene, I have a light transmitter (direct or diffusion source) that lights a room, the transmitter is placed anywhere in the room. The simulation is started and the lighting is calculated (the ligthing is not dynamic) but I have to move in the scene to see the result.

For the modelisation, I will probably use 3DSmax or blender.
I need a 3D engine (not GPL) that handles my custom light managment.
Which one could I use ? Free or not.
Do I need to make a raytracer ? Apparently it is 3D engine and graphical API independent ! If yes, how can I interface it with my engine ?
Are lightmaps prepared in the modelisation tool (3DSmax for instance) ?

Thanks for the help.

[Reedbeta]

If your own algorithm calculates the lighting, you could just store that into lightmaps, so all you'd need is an engine supporting lightmaps - which is a technology going back all the way to Quake. Maybe you could interface your lighting algorithm with a Max plugin in order to create the lightmaps - I don't really know much about it.

[Math]

Reedbeta said:

If your own algorithm calculates the lighting, you could just store that into lightmaps, so all you'd need is an engine supporting lightmaps - which is a technology going back all the way to Quake. Maybe you could interface your lighting algorithm with a Max plugin in order to create the lightmaps - I don't really know much about it.

Thanks for the answer.
Ok, so how can I define my lighting algorithm and how can I interface it with my 3D engine ?
I need to add a new "light" in the engine.

[Reedbeta]

You don't need to add a new light in the engine. You just need to generate the lightmaps as a pre-process, and then arrange for the engine to display the world with the textures and lightmaps, and no other lights. For any more details you'd have to consult the docs for the specific engine you're working with.

[Math]

Ok but, what I want to be is to move/change the light source in my application between two simulations.
Imagine a 3D application that deals with a room with objects, you put a light transmiter and launch a simulation, move the transmiter (evenutally change the intensity or other properties) and launch a second simulation.
If I use a max plugin, the lightmap will be precalculated... it will not work for me ??
Thanks.

[Reedbeta]

Hmm, I see. I doubt that any engine has a built-in feature that can be easily adapted to that - you'll need to code your algorithm into the engine in such a way that you can trigger it with a keystroke or something, and give it access to the lightmap textures that it needs to modify. In any case, you should decide on an engine and then start reading its docs and code in order to know how to proceed.

[Math]

Reedbeta said:

Hmm, I see. I doubt that any engine has a built-in feature that can be easily adapted to that - you'll need to code your algorithm into the engine in such a way that you can trigger it with a keystroke or something, and give it access to the lightmap textures that it needs to modify. In any case, you should decide on an engine and then start reading its docs and code in order to know how to proceed.

Ok, thanks.
So I don't have to handle lightmaps in 3dsmax ?
I will look to Ogre since it seems to be a powerful engine.
I assume I will have to code a raytracer !!!

[Math]

Hi,
Well, I made a mistake : it is not raytracing but in fact, I need a radiosity implementation.
I'm looking to FSRAD, a tool that generate lightmaps based on radiosity.
Does somebody knows FSRAD and has an opinion on it ?
If it is ok, I only need a good 3D engine that handles lightmaps.

[sirfalas]

Hey,

Do you want just a 3D engine or do you want a complete game engine?

If you only want a 3D engine, you could try Irrlicht. Check out the features here (http://irrlicht.sour.../features.html).

If you want something more specific, try going to http://www.gdse.com/ . You can use the search feature there to search for an engine that you want.

[Math]

Well, I don't need a complete game engine.
So Irrlicht + FSRAD is a good solution for me ?
Thanks.

[Reedbeta]

Math said:

So Irrlicht + FSRAD is a good solution for me ?

No one can answer that question but you. Why don't you just get the programs and start using them? You'll find out soon enough if they're suited to your purpose or not.