Point Light

This page offers information about imported and native Point lights in Chaos Vantage.

Overview

The Max Point Light is the representation of the Point light from 3ds Max in Chaos Vantage. It can be either created using the Create new Light object tool from the Toolbar or imported with a .vrscene file.

The Point Light is the representation of the Point light that is imported from any application except 3ds Max. It has fewer parameters than the Max Point Light.

Max Point Light Parameters

The following parameters are available when creating Max Point Light in Vantage or importing it from 3ds Max.

Enabled – Turns on and off the point light.

Color – Changes the color of the point light. See the Color example below.

Intensity – Specifies the intensity of the point light's brightness. See the Intensity example below.

Decay type – Sets the type of decay (reduction of a light's intensity over distance) to use for the light.

None – No decay is applied and the light maintains full strength to infinity unless Far attenuation is enabled.
Inverse – Applies a slow, forgiving falloff to the light, i.e., a gradual, soft, and aesthetically pleasing decrease in light intensity as it moves away from the light source. If you double the distance from the light source, the brightness is reduced in half. The decrease in the intensity can be calculated by the formula luminance=R0 /R where R0 is the Near attenuation end value of the light if enabled, and R is how far the surface is from that point (R0).
Inverse square – Applies a fast, physically accurate falloff to the light that matches the real-world light behavior. If you double the distance from the light source, the brightness is reduced 4 times. The decrease in the intensity can be calculated by the formula luminance=(R0 /R)2 where R0 is the Near attenuation end value of the light if enabled, and R is how far the surface is from that point (R0).

Decay start – Specifies the distance at which the light begins to decay. Value is ignored if Near attenuation is enabled.

Projector tex – Specifies the texture that would be used for color projection.

Load projector tex – Opens a browse window to load the texture to be used for projection.

Image gamma – Specifies the color space for the loaded Projector tex.

sRGB – Sets the loaded projector texture to be interpreted in sRGB color space.
Linear – Sets the loaded projector texture to be interpreted in Linear color space.
Auto – Automatically determines the color transfer function. If a bitmap file name contains the string "_srgb", the transfer function is sRGB. If a bitmap file name contains the strings "_lin_srgb" or "raw", no correction is applied. For bitmap files with 8 bits per color component, 3 or 4 color components (like png, jpg, and other) and no suffix, the transfer function is sRGB. In all other cases, no correction is applied.

Near attenuation – Enables near attenuation for the light.

Near attenuation start – Sets the distance at which the light begins to fade in.
Near attenuation end – Sets the distance at which the light is at full intensity.

Far attenuation – Enables far attenuation for the light.

Far attenuation start – Sets the distance at which the light begins to fade out.
Far attenuation end – Sets the distance at which the light is at zero intensity.

Shadow shape – Specifies the shape for the light from which shadow rays are cast.

Box – Sets a box shape the light.
Sphere – Sets a sphere shape the light.

U size – Specifies the length of the box shape when Shadow shape is Box or the diameter of the sphere Shadow shape is Sphere.

V size – Specifies the width of the box shape when Shadow shape is Box.

W size – Specifies the height of the box shape when Shadow shape is Box.

Shadows – When enabled (the default), the light casts shadows. Turn this option off to disable shadow casting for the light. The value moves the shadow toward or away from the shadow-casting object(s). Higher values move the shadow toward the object(s), while lower values move it away. If this value is too extreme, shadows can "leak" through places they shouldn't or "detach" from an object. Other effects from extreme values include Moire patterns, out-of-place dark areas on surfaces, and shadows not appearing at all in the rendering. See the Shadows example below.

Affect diffuse – Determines whether the light affects the diffuse portion of the materials. The value controls the light's contribution to the diffuse portion of the materials. See the Affect Diffuse example below.

Affect specular – Determines whether the light affects the specular portion of the materials. The value controls the light's contribution to specular reflections. See the Affect Specular example below.

Use global mult. – When enabled, uses the Enable Lights value (Render tab > Advanced mode > Lighting rollout) as a multiplier to Intensity value. When disabled, the light is independent from the global multiplier.

Soft shadows – When enabled, the light shape is considered for illumination and the light is going to generate soft shadows. When disabled, the light is going to generate sharp shadows.

Area speculars – When enabled, the shape of the light is visible in the specular reflections. When disabled, the particular light is rendered as a point light in the specular reflections.

Point Light Parameters

The following parameters are available when importing Point Lights from applications other than 3ds Max.

Enabled – Turns on and off the point light.

Color – Changes the color of the point light. See the Color example below.

Intensity – Specifies the intensity of the point light's brightness. See the Intensity example below.

Shadows – When enabled (the default), the light casts shadows. Turn this option off to disable shadow casting for the light. The value moves the shadow toward or away from the shadow-casting object(s). Higher values move the shadow toward the object(s), while lower values move it away. If this value is too extreme, shadows can "leak" through places they shouldn't or "detach" from an object. Other effects from extreme values include Moire patterns, out-of-place dark areas on surfaces, and shadows not appearing at all in the rendering. See the Shadows example below.

Affect diffuse – Determines whether the light affects the diffuse portion of the materials. The value controls the light's contribution to the diffuse portion of the materials. See the Affect Diffuse example below.

Affect specular – Determines whether the light affects the specular portion of the materials. The value controls the light's contribution to specular reflections. See the Affect Specular example below.

Use global mult. – When enabled, uses the Enable Lights value (Render tab > Advanced mode > Lighting rollout) as a multiplier to Intensity value. When disabled, the light is independent from the global multiplier.

Soft shadows – When enabled, the light shape is considered for illumination and the light is going to generate soft shadows. When disabled, the light is going to generate sharp shadows.

Area speculars – When enabled, the shape of the light is visible in the specular reflections. When disabled, the particular light is rendered as a point light in the specular reflections.

Examples

The following examples demonstrate the effect that individual Point Light parameters have on the scene. Click on any image to view it at a higher resolution.

Color

This example shows the effect of the Color parameter.

Color is red

Color is green

Color is blue

Intensity

This example shows the effect of the Intensity parameter.

Intensity = 50

Intensity = 100

Intensity = 200

Intensity = 300

Shadows

This example shows the effect of the Shadows parameter.

Shadows is off

Shadows is on

Affect Diffuse

This example shows the effect of the Affect diffuse parameter.

Affect diffuse is off

Affect diffuse is on

Affect Specular

This example shows the effect of the Affect specular parameter.

Affect specular is off

Affect specular is on