yet another lighting question

WToma · Post by **WToma** » Sat Aug 13, 2005 2:36 pm

i try to display 3ds files with irrlicht (0.11)
for some models lighting works correcty, the unlighted polygons appear black.
but for some others, I can see all polygons in its own colors. the lighted ones appear only brighter.
what can be the problem? what should I set?
Toma

disanti · Post by **disanti** » Sat Aug 13, 2005 4:49 pm

I wouldn't say that Irrlicht's lighting system is all that great... I'm trying to figure these bugs out myself, it could be the normals.
________
Friday night lights advice

luckymutt · Post by **luckymutt** » Sat Aug 13, 2005 6:03 pm

Someone correct me here if I am wrong...
but from what I understand, if you have a line like this:

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node->setMaterialFlag(video::EMF_LIGHTING, false);

then the material will just show up with the model, but if that value is set to true, then it will be relying on the lights that you add in by code to be able to see colors and materials.
At least that's been my impression.
I think a good lighting tutorial would be useful.

As a CG artist by profession, I can tell you that lighting and texturing are what seperates OK-ish work to "WOW"
You can train a monkey to place and manipulate primitives.

Anyway, since Irrlicht does have its own lighting system, it would be interesting to see various techniques.
This is a subject I'm trying to make the time to really jump into, but alas...there is never enough time.
(sorry for ramble)

WToma · Post by **WToma** » Sat Aug 13, 2005 7:12 pm

Well, about EMF_LIGHTING I have the same opinion. But is was not the solution. It was MY3D format that saved my life. Now I am happy and I put back the rope for harder times

Toma
ps: 3DS sux, MY3S for president!

luckymutt · Post by **luckymutt** » Sat Aug 13, 2005 7:21 pm

MY3D came along and saved your life within the past 5 hours?
wow.
So, does your original question pertain to the *3ds format or the *.My3D?

The only problem I have with MY3D are that the file sizes seem HUGE. I don't how much of a problem this might pose with the size levels that I want to achieve, maybe not at all.

Does anyone know if there is a performance issue related to model file size or poly count?

WToma · Post by **WToma** » Sun Aug 14, 2005 12:44 pm

The orginial question was about 3DS. But it's not a problem to use My3D since there is exporter for 3ds max (3ds to my3d: import the 3ds into max then export to my3d). I don't know what was the difference in the 3ds files, but it isn't important any more.
I think files are bigger because my3d stores additional information about the models (lightmaps, i think). And of course, the more polys you have, the more cpu time will be needed to draw everything.
Toma

Guest · Post by **Guest** » Sun Aug 14, 2005 1:29 pm

yet another one

can I place directional lights to the scene? addLightSceneNode places only a pointlight, doesn't it?
Toma

luckymutt · Post by **luckymutt** » Sun Aug 14, 2005 6:37 pm

I don't think so.
Nothing I could find in the API anyway...
I think it is only like an omni light.
A dircetional light would be very cool to have though...feel like coding one up?

WToma · Post by **WToma** » Mon Aug 15, 2005 9:42 am

Well, I will need it.
OpenGL supports it, but I have never coded in DX. Anyway, I must try it. I'll post my code here as soon as I manage to make it work.
Toma

WToma · Post by **WToma** » Mon Aug 15, 2005 5:17 pm

OK, it is up and working.
You can download it from here: http://sohivatal.uw.hu/dev/directional_light_patch.zip or from here: http://szerver2.radnoti-szeged.sulinet. ... _patch.zip
(note, the first is a hungarian free webspace provider, the second is the public server of my school and they may have very little bandwidth outside Hungary. if you find the source useful, please mirror it to your webspaces)
License: which Irrlicht has
Manual
Installation: simply update Irrlicht source with the files you got in the ZIP file. Build the source. It should compile without warning. Don't forget to use the new headers and binaries (.a, .dll, .lib)
Usage: to create a directional light, call

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ISceneManager::addDirectionalLightSceneNode

parameters:

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ISceneNode* parent node, can be NULL
vector3df& position of the light source (default: 0,0,0)
vector3df& direction of the light source (degrees) (default: 0,0,-1)
SColorf color of the light (default: full white)
f32 radius of th light (default: 100)
s32 id (default: -1)

return value:
an IDirectionalLightSceneNode pointer. You can use all functions you can use with an ILightSceneNode.
Notes
1. for OpenGL-ers: the cutoff angle is 90°, you can change in COpenGLDriver.cpp line 1618
2. there is an example/test source in the dirlight_test directory.
3. Tested with OpenGL, DX8 and DX9) renderers. Not implemented in software renderer.
Enjoy and use it on your own risk!

Toma