LuxCoreRender Forums

Hi,

I've tried to replace the circle with a square plane. (Edge size 2mm)
It should be 2 tris only, am I right? It's still crashing while using angles below 20 degrees.

BR

lighting_freak wrote: Sat Feb 10, 2018 12:25 pm I've tried to replace the circle with a square plane. (Edge size 2mm)
It should be 2 trial only, am I right? It's still crashing while using angles below 20 degrees.

It is still too small, just use a laser light source or a spot light.

Hi,

with "laser light source" you're meaning the "Area" option, or did I miss anything in new lux core?
BR

lighting_freak wrote: Sun Feb 11, 2018 11:06 am Hi,

with "laser light source" you're meaning the "Area" option, or did I miss anything in new lux core?

light_sources.JPG

BR

This:

Hi

This:

laser.jpg

Sure...

One more question, why is the amount of emitted energy depending on the spread angle?
In my mind each surface element (tri) emits light dependent on it size (area) but not the direction.
Thanks.

BR

lighting_freak wrote: Sun Feb 11, 2018 7:55 pm One more question, why is the amount of emitted energy depending on the spread angle?
In my mind each surface element (tri) emits light dependent on it size (area) but not the direction.

At the moment, theta parameter just "cut" the emitted light (like if it was obstructed), it doesn't increase the emitted light when you decrease the angle. Yes, it would be more correct to keep the total emitted power constant.

Hi,

does that mean, that I don't get 1 lumens output if I enter 1 lumen (1 watt and 1 efficiacy) and an angle smaller 90deg?

BR

lighting_freak wrote: Mon Feb 12, 2018 6:57 pm does that mean, that I don't get 1 lumens output if I enter 1 lumen (1 watt and 1 efficiacy) and an angle smaller 90deg?

Yup, you get less. You should get (1.0 - cos(theta)) lumen.

Hi,

This points directly to the next question... how is the energy management in area and laser light sources?
How do you solve this in volume emitters?

It might be to early to push functionality requests to you but do you think it might be possible to change the material emitter into an energy consistent one?

BR

lighting_freak wrote: Tue Feb 13, 2018 5:57 am This points directly to the next question... how is the energy management in area and laser light sources?

It is correct as far as I know, only theta is an after tough. Theta is bit a problem because it is like defining 3 types of different light sources:

- Theta = 0 => it is like a laser light source

- 0 < Theta < 90 => it is light a spot light source

- Theta = 90 => it is normal area light source

The sampling used in the 3 cases is different so not updating energy management was a short cut for theta < 90.

lighting_freak wrote: Tue Feb 13, 2018 5:57 am How do you solve this in volume emitters?

It is considered a set of point lights with the specified parameters (and at the moment, it is only a scalar RGB value without power/efficiency).

lighting_freak wrote: Tue Feb 13, 2018 5:57 am It might be to early to push functionality requests to you but do you think it might be possible to change the material emitter into an energy consistent one?

Yes, I'm going to sort out the energy consistency with theta (everything else should be consistent as far as I know).