What is the real world equivalent of a point light with a radius so large that it envelops the objects you are shining the light on.
Blender is famous for it’s strange UI names for stuffs…they represent add cones with a cube…
The real world equivalent is a spherical light surrounding an object. The point light acts as a spherical area light if radius is nom-zero
So a circular room with glowing walls and my camera and subject are within that?
open default scene
replace default cube with suzanne
increase radius of default light to 10m so it surrounds suzanne and the default camera
snap cursor to the default light
add an icosphere
scale sphere until it is 10m in size.
This is much much smaller than the light size indicator circle. Why?
Increase sphere size until it matches the light.
Add emission material to sphere.
Reduce world strength to zero.
Render with the light only.
Render with the sphere only.
Compare renders.
The sphere test looks identical to if I had made the world background color white with a strength of one.
So I do not think it is correct to say “The real world equivalent is a spherical light surrounding an object.” unless I misunderstand what you meant by “spherical light”.
The point light size is the radius of the sphere, not the diameter. The “size” readout in Blender is the bounding box dimensions, which would correspond to diameter of the sphere, not radius.
And looks like the way Cycles samples point lights is not designed for the point light to envelop things. So, I guess it’s more accurate to say it’s treated as a spherical area light for objects not inside the sphere. (mesh lights are double sided in Cycles, so a true spherical mesh light also shines inward).
Btw, “area light” has a specific meaning in 3D rendering, it refers to a light source that has an actual size in the world(such as a plane or a sphere or a cylinder or whatever), as opposed to an infinitesimal point or light coming from a particular direction at infinity.
Point lights are designed to simplify rendering, so they round off some corners in term of accuracy, especially at edge cases.
Scaling up a point light to include the entire scene is definitely an edge case.
So, to answer your original question, there is no real world equivalent. You are doing something that would never exist in the real world.
But I’ve downloaded quite a few .blend files from around the web that use absolutely massive point lights for some reason. They maybe don’t surround the entire scene but they surround large chunks of it.
Don’t assume 3D files you find on the internet were made people who knew what they were doing. Or hell, sometimes they do know but like the look of the artifacts from the mistake. “Huge point light surrounds entire scene” is nowhere close to the strangest project file I’ve ever seen.
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