How to set target or position of lights?

[hit2501]

Hi everyone,

Is there any image or similar like this where I can see how to positionate lights (hemispheric or directionals)

 

I dont understand the three coordinates system.

Sorry if this is a too "noob" question.

Thank you all.

[Wingnut]

Hi hit... that is not a noob question... no need to apologize. 

Direction vectors are sometimes difficult to understand.  But .position vectors for lights... is easy, though.  It works the same as mesh .positions.  With Z-facing camera (common)... X is left/right, Y is up/down, and Z is forward/backward. 

I will soon write a helper section in our Lights Tutorial... about directions.  Perhaps I will give a copy to @JohnK for HIS Lights Tutorial, too. 

For now, know that there is a method:   light.setDirectionToTarget(something.position) ...that will help you.

Hemi lights almost always aim straight up... direction 0, 1, 0 and their .position is usually 0,0,0 (scene center) and rarely changed.

SpotLights and DirectionalLights are the lights that MOST USE  .setDirectionToTarget().  THEIR .position is VERY important... because their .position is used for shadows creation.  PointLights also have important .position for same shadow reason, but a pointLight is ALL-direction. 

I am hurried now, but you can put camera and spotlight inside doubleside box... and experiment aiming spotlight with setDirectionToTarget()... and then checking console.log(spotLight.direction).  You will learn direction vectors fast... when doing that.  Good luck... I'll be back later.  Hope this helps.

[hit2501]

Thank you very much Wingnut, setDirectionToTarget(target) is what I was looking for.