Category:LSL Light

Light sources

Headline text

Controlling Light sources

Light in SL is determined by the OpenGL standard which allows for eight lights. Traditionally and practically, two sources are reserved for the Sun and Moon, leaving six for incidental lighting. All eight are really generated on the client-side video card, so different video card models may show the same scene slightly differently. If more than six user light sources are present in a scene, only the light from the closest six will show in the environment.

An example - How to generate, switch and change light from LSL:

// simple light source demonstrator
// 8feb07 "tetsumo kuri"
// thanks to squee janitor for line to dissect

integer light_s = TRUE;     //  "_s" for status

default
{
    state_entry()
    {
      //  llSetText("click me",<1,0,0.6>,.5);  // in case you like labels
    }

    touch_start(integer total_number)
    {
        if ( light_s )
        { 
            light_s = FALSE;

            // fullbright doesn't have anything to do with light in NEW(2006?) lighting model 
            // setting fullbright does look good though
            llSetPrimitiveParams([PRIM_FULLBRIGHT,ALL_SIDES,FALSE]);
              
            llSetPrimitiveParams([PRIM_POINT_LIGHT, FALSE,   // if this is false, light is off,
                                     <0.0,1.0,0.0>,1.0, 10.0, 0.5]); // rest of params don't matter
        }            
        else
        {
            light_s = TRUE;
            //llSetPrimitiveParams([PRIM_FULLBRIGHT,ALL_SIDES,TRUE]);   //leave fullbright commented for now
            llSetPrimitiveParams([PRIM_POINT_LIGHT,TRUE,
                                    <1.0,0.7,1.0>,  // light color vector range: 0.0-1.0 *3
                                    1.0,            // intensity    (0.0-1.0)
                                    10.0,           // radius       (.1-10.0)
                                    0.6 ]);         // falloff      (.01-1.0)
                
            // this could have been done in one line, like this     
            //llSetPrimitiveParams([PRIM_FULLBRIGHT,ALL_SIDES,FALSE,PRIM_POINT_LIGHT,TRUE,<1.0,1.0,0.5>,20,1.0,0.5]);
            //      ... but thats kinda hard to take in...       
        }
        //llSay(0, " Click!");
    }
}