[Solved] [2.1] Multiple point lights problem Topic is solved

[Dark_Mark]

Hi. I made a copy of the Sample_ShadowMapDebugging project to learn OGRE 2.1 by example. So far I only made some very minor changes to it, like replacing existing cubes with a different mesh and removing debug overlay elements. However, some strange problem occurs ever since I changed the type of all lights to LT_POINT, like this:

Code: Select all

Ogre::Light *light = sceneManager->createLight();
Ogre::SceneNode *lightNode = rootNode->createChildSceneNode();
lightNode->attachObject( light );
light->setPowerScale(Ogre::Math::PI);
light->setType( Ogre::Light::LT_POINT );
light->setAttenuationBasedOnRadius(10.0f, 0.01f);
mLightNodes[0] = lightNode;

light = sceneManager->createLight();
lightNode = rootNode->createChildSceneNode();
lightNode->attachObject( light );
light->setDiffuseColour( 0.8f, 0.4f, 0.2f ); //Warm
light->setSpecularColour( 0.8f, 0.4f, 0.2f );
light->setPowerScale( Ogre::Math::PI );
light->setType( Ogre::Light::LT_POINT);
lightNode->setPosition( -10.0f, 10.0f, 10.0f );
light->setAttenuationBasedOnRadius( 10.0f, 0.01f );
mLightNodes[1] = lightNode;

light = sceneManager->createLight();
lightNode = rootNode->createChildSceneNode();
lightNode->attachObject( light );
light->setDiffuseColour( 0.2f, 0.4f, 0.8f ); //Cold
light->setSpecularColour( 0.2f, 0.4f, 0.8f );
light->setPowerScale( Ogre::Math::PI );
light->setType( Ogre::Light::LT_POINT);
lightNode->setPosition( 10.0f, 10.0f, -10.0f );
light->setAttenuationBasedOnRadius( 10.0f, 0.01f );
mLightNodes[2] = lightNode;

For some reason, the scene cannot be lit by more than two point lights at once. The first light (white) is always active, but the other two exclude each other: either the orange one works or the blue one works, depending on whichever is closer to the camera:


Question is, how can I make OGRE display more than two point lights at once? Do I have to do something with compositor, turn on Forward3D or is it some kind of bug? Also, I don't really need multiple shadows, just one would be perfect.

[xrgo]

turn on Forward3D

that's it!.. non shadowcasting lights goes through forward+ (3D/Clustered) to be rendered, and since you might have just one shadow map for pointlight in your compositor ogre switches to the closest one (I think) to use the shadow map, and thats the one being rendered. enable forward+ and you will see both lights but the shadow will continue toggling unless you add another shadow map in the compositor shadow node

[Dark_Mark]

Well wasn't that easy after all. I turned on Forward3D like this:

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sceneManager->setForward3D(true, 4, 4, 5, 96, 3, 400);

And then disabled shadow casting for all lights but one:

Code: Select all

Ogre::Light *light = sceneManager->createLight();
Ogre::SceneNode *lightNode = rootNode->createChildSceneNode();
lightNode->attachObject( light );
light->setPowerScale(Ogre::Math::PI);
light->setType( Ogre::Light::LT_POINT );
light->setAttenuationBasedOnRadius(10.0f, 0.01f);
light->setCastShadows(false);
mLightNodes[0] = lightNode;

light = sceneManager->createLight();
lightNode = rootNode->createChildSceneNode();
lightNode->attachObject( light );
light->setDiffuseColour( 0.8f, 0.4f, 0.2f ); //Warm
light->setSpecularColour( 0.8f, 0.4f, 0.2f );
light->setPowerScale( Ogre::Math::PI );
light->setType( Ogre::Light::LT_POINT);
lightNode->setPosition( -10.0f, 10.0f, 10.0f );
light->setAttenuationBasedOnRadius( 10.0f, 0.01f );
mLightNodes[1] = lightNode;

light = sceneManager->createLight();
lightNode = rootNode->createChildSceneNode();
lightNode->attachObject( light );
light->setDiffuseColour( 0.2f, 0.4f, 0.8f ); //Cold
light->setSpecularColour( 0.2f, 0.4f, 0.8f );
light->setPowerScale( Ogre::Math::PI );
light->setType( Ogre::Light::LT_POINT);
lightNode->setPosition( 10.0f, 10.0f, -10.0f );
light->setAttenuationBasedOnRadius( 10.0f, 0.01f );
light->setCastShadows(false);
mLightNodes[2] = lightNode;

And now the lights seem to be working fine:


Thanks for the help! Are there any lighting limitations I should know about, such as maximum number of lights or performance issues with Forward3D?

[al2950]

FYI I would use setForwardClustered as it is faster. These algorithms are good all rounders and work on most setups. However there is a fairly fixed performance hit ( ie does not matter how many lights or scene complexity) per scene pass. This performance hit (which is a CPU hit) can be reduced by changing some of the settings of the forward* grid.

[Dark_Mark]

FYI I would use setForwardClustered as it is faster.

Thanks, I had no idea that this method existed.