Index

• Overview
• Headlight
• Light Object
  • Pointlight
  • Spotlight
  • Direction Light
• Fog

Overview

Building the 3D scene, in addition to creating models, setting colors and tiles on models, requires a lighting effect to more realistically reflect real-world scenes. This manual will introduce headlight, point light, spotlight and directional light in depth such as the various configuration parameters of light source, as well as fog and other effects.

Headlight

The HT is built with a headlight in default, the headlights equivalent to the eye position of graph3dView.getEye() has a point light, where the source of the light is changed with graph3dView.getEye(), so even if the user does not do any lighting settings, roaming to any location can experience the basic lighting effect.

Graph3dView controls the headlights through the following parameters:

• headlightRange: The lamp influence range, the default is 0 representative it cal illuminate to the infinite distance, if set the value then the light exposure effect will fade with the object away from the shadow
• headlightColor: The color of the light
• headlightIntensity: Light intensity, default is 1, if greater than 1 then enhance the intensity, if less than 1 then weakening the intensity
• headlightDisabled: Turn off the lighting effect, the default is false, can be set to true to turn off the light effect

Light Object

HT provides ht.Light type of data that inherits from ht.Node, by creating ht.Light type of data object, then add to the DataModel data model to achieve the effect of adding lights. The following light source types point light, spotlight and directional light are all controlled by ht.Light object, the following is the common style attribute of the lighting type:

• light.type: Default to point spot light, can be set to spot spotlight, and directional directional light type
• light.color: The color of light
• light.intensity: Light intensity, defaults to 1, if greater than 1 then enhance the intensity, if less than 1 then weaken the intensity
• light.disabled: Turns off the lighting effect, defaults to false and can be set to true to turn off the light effect

Remove ht.Light object from DataModel, with the light.disabled property set to false can be turned off the lighting effect, but the delete operation is heavy from the DataModel, it is recommended that to delete it while in long time do not use it, if you want to achieve frequent changes in flicker and other effects, the proposed light.disabled control is more efficient.

Point Light

Light is emitted from all directions in its position, affecting all objects within its length range.

• Point Light light source position is decided by the central location of the object ht.Light, that is, light.p3() value
• light.range: The light affects range, the default is 0 represents to be able to illuminate to infinite distance, if set the value then the light exposed effect decays with the object away from the shadow.

Spotlight

The spotlight is affected by objects within the specified fillet and length range, from where it is, to the position of the center point.

• Spotlight light source position is decided by the central location of the object ht.Light, that is, light.p3() value
• light.center: The location of the center point of the light source direction, the default is the origin [0, 0, 0]
• light.range: The light affects range, the default is 0 represents can illuminate to the infinite distance, if set the value then the light exposed effect with the object away from the shadow and fade
• light.angle: The angular curvature of the light, in which the object is affected by the light source
• light.exponent: Light exposure attenuation index, the default is 0, the greater the value of the object farther away from the center is affected by the light effect weaker

Directional Light

The directional light is in the infinite distance, in the direction specified to illuminate all objects in the scene, the sun is the application of such light.

• Directional light direction of illumination is determined by the ht.Light object center point to the 3D coordinate origin [0, 0, 0] vector direction, so changing the center point position of the light object can change the direction of illumination.

Fog

HT provides an fog effect that renders the scene shrouded in atomization, and Graph3dView is controlled by the following parameters:

• fogDisabled: The default is false does not enable fog effect, can be set to true to enable fog effect
• fogColor: The color of fog
• fogNear: The default is 1, which represents that the object starts to be affected by the fog effect from the distance
• fogFar: The default is 2000, which means that the object is completely invisible from the distance