SpotLight

WLJS

Execution environment

Supports dynamics

SpotLight[color_RGBColor, opts___]
SpotLight[color_RGBColor, position_, opts___]
SpotLight[color_RGBColor, {position_, target_}, opts___]
SpotLight[color_RGBColor, {position_, target_}, angle_, opts___]

places a fake source of spot light in a 3D scene (see Graphics3D). The default target is $\{0,0,0\}$.

Graphics3D[{Shadows[True], Polygon[ {{-5,5,-1}, {5,5,-1}, {5,-5,-1}, {-5,-5,-1}}], White, Cuboid[{-1,-1,-1}, {1,1,1}], Directive["Shadows"->False], PointLight[Red, {1.5075, 4.1557, 2.6129}, "Intensity"->50], Directive["Shadows"->True], SpotLight[Cyan, {-2.268, -2.144, 3.1635}]}, "Lighting"->None]

For the best effect, use Shadows set to True

warning

In the case of "PathTracing" renderer, spot light can only work properly if "MultipleImportanceSampling" is enabled in the options of Graphics3D

Options

"Intensity"

By the default is 100

"Decay"

"Penumbra"

"ShadowBias"

"ShadowMapSize"

See THREE.js docs

Dynamics

position and target do support updates

pos = {0,0,2};
handler = Function[data, pos = data];

KnotData[{"TorusKnot", {3, 5}}][[1]];
Graphics3D[{ Shadows[True],
  %, 
  EventHandler[Sphere[pos, 0.1], {"drag" -> handler}], 
  SpotLight[White, {Offload[pos], {0,0,0}}],
  Polygon[5{{-1,1,-1}, {1,1,-1}, {1,-1,-1}, {-1,-1,-1}}]
}, "Lighting"->None, ImageSize->600]