Analytic lights Tweet

[Rik]

How do you change the power of an analytic light? Do you have to use a blackbody emission map

Also, why am I getting longer render times using newer features?

Standard Octane light (not with vectron ticked) 19 seconds
Standard Octane light with vectron ticked 20 seconds
Analytic light 21 seconds

Surely the renders should be getting faster with later features (vectron then analytic) instead they're slower.

[paride4331]

Hi Rik,
Considering the characteristics of the analytic lights (which I'll describe at the bottom), I also achieve greater cleanliness in PT (Path Tracing). You can see it by comparing the noise layer, with a saving, in this case, of two minutes, for example.
Analytic light primitives offer a fast approximation of direct light from large direct light sources on diffuse or glossy materials. Every sample the complete contribution is estimated, taking into account the roughness of the material and the shape of the light source. It is important to note that there is currently a maximum of 8 supported in the scene.
The primitives Disk, Sphere, Tube and Quad Light are similar to mesh lights but have custom low noise light sampling. The direct lighting for up to 8 analytic lights is calculated at once, allowing fast navigation with noise free direct light even at 1 sample per pixel.
Regards
Paride

[Rik]

Soooo your saying these new analytic lights only work when using direct light kernel as opposed to path tracing?

And is an emission texture the only wat to control how bright they are?

[elsksa]

Soooo your saying these new analytic lights only work when using direct light kernel as opposed to path tracing?
And is an emission texture the only wat to control how bright they are?

He was referring to direct lighting as rays, not the kernel.

And is an emission texture the only wat to control how bright they are?

The light properties panel should show various parameters.