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Why does a point light not cast shadows when using IRAY?

FlortaleFlortale Posts: 611
in New Users

I'm using IRAY.   I have Genesis 8.   The Dome shadow is working, but the point light isn't casting any shadow on the ground.  On the point light, under LIGHT, there are three settings: Shadow, Area, Photometrics.  The Shadow setting is disabled.

How do you get point lights to cast shadows using IRAY?

I think I need an IRAY indoor lighting tutorial or something.  Like how to light  a basic room with a lamp.

Comments

  • SimonJMSimonJM Posts: 5,999

    It might be doing so, but has it anything to cast a shadow upon?  Also if the light is very close to the object teh shdow woudl be very broad and hard to make out.  For Iray teh photometric setting shoudl be on, and you'll need to increase it's output (using the Iray-tralted settings) to very big numbers for the light putput to be noticeable.

  • FlortaleFlortale Posts: 611
    SimonJM said:

    It might be doing so, but has it anything to cast a shadow upon?  Also if the light is very close to the object teh shdow woudl be very broad and hard to make out.  For Iray teh photometric setting shoudl be on, and you'll need to increase it's output (using the Iray-tralted settings) to very big numbers for the light putput to be noticeable.

    You're right. I needed to add a ground. Now the point light casts a shadow.

    Do you know how to control a point lights shadow softness?

  • rames44rames44 Posts: 332

    If you want a soft shadow, you don’t want a point light. Either use a spotlight (and change it to have an area, rather than being a point itself) or else use an object set to emit. 

    Soft shadows are fundamentally the result of the fact that the light is NOT emitted all from a single point, and so some “leaks past” the target object around the edges. 

  • FlortaleFlortale Posts: 611
    rames44 said:

    If you want a soft shadow, you don’t want a point light. Either use a spotlight (and change it to have an area, rather than being a point itself) or else use an object set to emit. 

    Soft shadows are fundamentally the result of the fact that the light is NOT emitted all from a single point, and so some “leaks past” the target object around the edges. 

    So in the case of a lamp. I should just select the lamp shade and set it to emit light?

  • FishtalesFishtales Posts: 6,162
    liplin901 said:
    rames44 said:

    If you want a soft shadow, you don’t want a point light. Either use a spotlight (and change it to have an area, rather than being a point itself) or else use an object set to emit. 

    Soft shadows are fundamentally the result of the fact that the light is NOT emitted all from a single point, and so some “leaks past” the target object around the edges. 

    So in the case of a lamp. I should just select the lamp shade and set it to emit light?

    If it has a bulb use that with the Emissive shader.

  • rames44rames44 Posts: 332
    Fishtales said:
    liplin901 said:
    rames44 said:

     

    So in the case of a lamp. I should just select the lamp shade and set it to emit light?

    If it has a bulb use that with the Emissive shader.

    Yes - having the shade emit probably wouldn’t look right.  If the lamp doesn’t have a bulb, or if you want to experiment with alternatives (which is always a good idea) you could create a small sphere, position it inside the lamp and set it to use an emissive shader.

    Note that interior scenes (if that’s what you’re doing) can be challenging to light...

  • BeeMKayBeeMKay Posts: 7,019

    A word of warning - in emissive lights, light is calculated per emissive polygone of the surface. So if you have a lot of emissive polygones, render times might go up.

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