lights initial

proto/decentraland/sdk/components/global_light.proto

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+syntax = "proto3";
+package decentraland.sdk.components;
+
+import "decentraland/common/colors.proto";
+import "decentraland/common/vectors.proto";
+
+import "decentraland/sdk/components/common/id.proto";
+option (common.ecs_component_id) = 1206;
+
+// defines the global scene light settings. must be added to the scene root.
+// to control sunlight color, intensity, shadows etc, you can also add a PbLight to the scene root.
+message PbGlobalLight {
+  // the direction the directional light shines in.
+  // default depends on time of day and explorer implementation
+  optional decentraland.common.Vector3 direction = 1;
+  // ambient light color
+  // default: White
+  optional decentraland.common.Color3 ambient_color = 2;
+  // ambient light intensity. the explorer default ambient brightness is multiplied by this non-physical quantity.
+  // default 1
+  optional float ambient_brightness = 3;
+}

proto/decentraland/sdk/components/light.proto

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+syntax = "proto3";
+package decentraland.sdk.components;
+
+import "decentraland/common/colors.proto";
+
+import "decentraland/sdk/components/common/id.proto";
+option (common.ecs_component_id) = 1204;
+
+// defines a light source.
+// the world has a default directional light (like sunlight) which can be overridden by adding the light component to the scene root.
+// a PbGlobalLight component can also be added to the root to control the directional light direction.
+// point lights (lightbulbs) or spotlights can be created by attaching the light component to non-root entities.
+message PbLight {
+  // whether the light is on
+  // default true
+  optional bool enabled = 1;
+  // light brightness in lux (lumens/m^2). 
+  // 
+  // for global directional light, this applies as a constant value at all surfaces and distances (though the effect on the surface still depends on incidence angle).
+  // the default global light illuminance varies from 400 (sunrise/sunset) to 10,000 (midday).
+  // for typical values, see https://en.wikipedia.org/wiki/Lux#Illuminance
+  //
+  // for point and spot lights, this is the lumens/m^2 at 1m distance from the light. to transform from raw lumens, 
+  // divide lumens by ~12 (4*pi).
+  // e.g. a 100w household bulb with 1200 lumens would have an illuminance of ~100.
+  // a lighthouse bulb with 200,000 lumens would have an illuminance of ~15,000 (ignoring beam reflections)
+  // 
+  // default 
+  // for point/spotlights: 10,000
+  // for global directional light: depends on explorer implementation. may vary on light direction, time of day, etc
+  optional float illuminance = 2;
+  // whether the light should cast shadows.
+  // note: even when set to true the engine may not display shadows, or may only show shadows for a limited number 
+  // of lights depending on the implementation, platform, and user settings.
+  // default
+  // for point/spotlights: false / off
+  // for global directional light: true / on
+  optional bool shadows = 3;
+  // light color
+  // default White
+  optional decentraland.common.Color3 color = 4;
+}

proto/decentraland/sdk/components/spotlight.proto

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+syntax = "proto3";
+package decentraland.sdk.components;
+
+import "decentraland/sdk/components/common/id.proto";
+option (common.ecs_component_id) = 1205;
+
+// defines a spotlight.
+// spotlights are point lights that emit light only in a cone around the transform's forward direction.
+// add this component together with the PbLight component to transform a point light into a spotlight.
+// note that spotlights do not model any internal reflections / focus, they only restrict the area of effect.
+// so for e.g. a torch beam, the bulb illuminance should be multiplied by the solid angle. 
+// a typical torch with a beam width of 15 degrees would use outer angle of 0.15 (7.5 degrees in radians),
+// and an illuminance approximately equal to the bulb's lumens, e.g. 1200.
+message PbSpotlight {
+  // the cone radius in radians. distance away from forward in which the light is visible. 
+  // for a torch a value around 0.15 is appropriate.    
+  float angle = 1;
+  // optional angle at which the light is brightest. should be <= outer angle. 
+  // if specified, the light will fall off smoothly between `inner_angle` and `angle`.
+  optional float inner_angle = 2;
+}