OpenGL Volumetric Lighting

varmint · Post by **varmint** » Wed Jan 02, 2008 9:45 pm

Over the holidays and in between family stuff

I thought it'd be kewl to have some volumetric lighting in Irrlicht for flashlights, car lights, street lights, etc. I looked around and didn't see anything so whipped up this little thing.

It's far from 100% and could still use some work, but it's far enough along for our purposes, so I figured to post it for others.

Feel free to use it / modify it and improve it.

It's been tested in Mac and Windows and against the latest SVN head.

I started with CCubeSceneNode frame and went from there.

1) in ISceneManager.h add the following just before addCubeSceneNode

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		//! adds Volume Lighting Scene Node.
		//! the returned pointer must not be dropped.
		virtual ISceneNode* addVolumeLightSceneNode(ISceneNode* parent=0, s32 id=-1,
			const s32 subdivU = 32, const s32 subdivV = 32,
			const video::SColor foot = video::SColor(51, 0, 230, 180),
			const video::SColor tail = video::SColor(0, 0, 0, 0),
			const core::vector3df& position = core::vector3df(0,0,0),
			const core::vector3df& rotation = core::vector3df(0,0,0),
			const core::vector3df& scale = core::vector3df(1.0f, 1.0f, 1.0f)) = 0;

2) in CSceneManager.h add the following just before addCubeSceneNode

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		//! adds Volume Lighting Scene Node.
		//! the returned pointer must not be dropped.
		virtual ISceneNode* addVolumeLightSceneNode(ISceneNode* parent=0, s32 id=-1,
			const s32 subdivU = 32, const s32 subdivV = 32,
			const video::SColor foot = video::SColor(51, 0, 230, 180),
			const video::SColor tail = video::SColor(0, 0, 0, 0),
			const core::vector3df& position = core::vector3df(0,0,0),	const core::vector3df& rotation = core::vector3df(0,0,0),	const core::vector3df& scale = core::vector3df(1.0f, 1.0f, 1.0f));

3) In CSceneManager.cpp add the following just before #include "CCubeSceneNode.h"

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#include "CVolumeLightSceneNode.h"

4) In CSceneManager.cpp add the following just before addCubeSceneNode block

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//! adds Volume Lighting Scene Node.
//! the returned pointer must not be dropped.
ISceneNode* CSceneManager::addVolumeLightSceneNode(ISceneNode* parent, s32 id,
	const s32 subdivU, const s32 subdivV,
	const video::SColor foot,
	const video::SColor tail,
	const core::vector3df& position, const core::vector3df& rotation, const core::vector3df& scale)
{
	if (!parent)
		parent = this;

	ISceneNode* node = new CVolumeLightSceneNode(parent, this, id, subdivU, subdivV, foot, tail, position, rotation, scale);
	node->drop();

	return node;
}

5) Now copy and add CVolumeLightSceneNode.cpp and CVolumeLightSceneNode.h to your project and build irrlicht.

To use I used the meshViewer to test it. Add the following code, I added it just before the main loop to draw everything.

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	//test for volume lighting
	scene::ISceneNode * n = smgr->addVolumeLightSceneNode(NULL, -1, 
								32, //Sub Divid U
								32, //Sub Divid V
								video::SColor(30, 255, 255, 255),	//foot colour
								video::SColor(0, 255, 0, 0)			//tail colour
								);
	
	if (n) {
		n->setScale(core::vector3df(66.0f, 75.0f, 66.0f));
		video::SMaterial& mat = n->getMaterial(0);
		mat.setTexture(0, smgr->getVideoDriver()->getTexture("lightFalloff.png"));
	}

Code Links
http://shadow.krabbit.com/varmint/volLi ... neNode.cpp
http://shadow.krabbit.com/varmint/volLi ... ceneNode.h
test image
http://shadow.krabbit.com/varmint/volLi ... alloff.png

enjoy

FuzzYspo0N · Post by **FuzzYspo0N** » Sat Jan 05, 2008 12:00 am

wow varmint thats really cool!

Im gonna look at including it in my game that im making now, just for fun...

I like the way u use it too, its neat.

FlyingIsFun1217 · Post by **FlyingIsFun1217** » Sat Jan 05, 2008 12:18 am

I can't wait to see more of these kind of things added into the main SVN branch, so that multiple people start looking through it and make it even better

FlyingIsFun1217

MasterGod · Post by **MasterGod** » Sat Jan 05, 2008 2:43 am

It Looks Amazing!! - If something like this isn't going into the library core I'm gonna kill someone

bitplane · Post by **bitplane** » Sat Jan 05, 2008 5:39 pm

Wow how did I miss that? Looks really cool.
To be included in the engine it would need the new material stuff to be in an IMaterialRenderer, and the drawing the buffer part use drawMeshBuffer. And of course directx materials too.
May use it myself as it is though

Dorth · Post by **Dorth** » Sat Jan 05, 2008 6:38 pm

Hmmm, may I suggest a patch/addition forum to be added? Maybe people could only reply and dev post/move topics there?

That way, good things like this and a couple of others wouldn't get lost in the pile. Either they'd adapt tobe included, were included or take too much time / no longer be needed and moved back to another topic / closed. That way, active stuff is all and any topic open in that section.

varmint · Post by **varmint** » Sun Jan 06, 2008 9:17 am

thx for comments

I'm always shy about me code

Just posted an update. Works better now in scenes and stuff.

varmint · Post by **varmint** » Sun Jan 06, 2008 9:18 am

bitplane wrote:Wow how did I miss that? Looks really cool.
To be included in the engine it would need the new material stuff to be in an IMaterialRenderer, and the drawing the buffer part use drawMeshBuffer. And of course directx materials too.
May use it myself as it is though

I'd love to add it in with DirectX support. Problem I was having and reason for calling opengl commands directly is I didn't see a way to set the footer and tail colours of the verts, with Alpha. Is there away to do this?

I dew have a

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	driver->setMaterial(Buffer->Material);
	driver->drawVertexPrimitiveList(
			Buffer->getVertices(), Buffer->getVertexCount(),
			Buffer->getIndices(), Buffer->getIndexCount() / 4 ,
			Buffer->getVertexType(), EPT_QUADS);

in there.. intended for this purpose

Also I'm working on motion trails based on the same type of logic, using QUADS.. I could add that in too

It uses Empty Scene Nodes as markets were to render them.

varmint · Post by **varmint** » Sun Jan 06, 2008 9:34 am

actually I was working with EMT_ONETEXTURE_BLEND and pack_texureBlendFunc i can probably dew it with

hybrid · Post by **hybrid** » Sun Jan 06, 2008 9:34 am

You should change to tri lists/strips for cross driver compatibility, because quads are not supported in d3d.

MasterGod · Post by **MasterGod** » Sun Jan 06, 2008 1:07 pm

1. Awesome

2. Please post more screen shots

varmint · Post by **varmint** » Sun Jan 06, 2008 1:32 pm

Converted to tris and added to SVN trunk.

Direct 3D 9 Screenie

OpenGL on OSX screenie

MasterGod · Post by **MasterGod** » Sun Jan 06, 2008 2:11 pm

No way it looks so good!!!
Amazing work there varmint!! I Love it.

etcaptor · Post by **etcaptor** » Sun Jan 06, 2008 6:12 pm

Awesome! This is will be a great addition to engine.

doqkhanh · Post by **doqkhanh** » Sun Mar 02, 2008 7:51 am

Thank you very much. This is great feature!
But my demo program has been crashed after replaced irrlicht.dll with new dll build from modified code by your topic.

Irrlicht Engine

OpenGL Volumetric Lighting

OpenGL Volumetric Lighting

thanksssss...