Introduction


  • This lesson will take you through creating a Dome light in V-Ray for Maya
  • The information centers around the use of the VRayLightDome
  • This lesson topic is approximately 30 minutes in length
  • Lesson covers all 3 Learning Cycles for the Lesson Topic – Lecture, Demonstration, and Activity.
  • Learning Outcomes: You will be able to light a scene with a VRayLightDome and understand how to adjust the settings to creating the look you want in your renders

Contents


Overview
Available Materials
Lecture
Demonstration
Activity
Additional Resources


Overview


Goal - Develop the look for our miniature house set, to create something that has a cinematic feel.

Objective - We will light a scene with the VrayLight and understand how to get the desired results.

Outcome - You will be able to adjust the V-Ray Dome Light to create different cinematic looks to your renders.

 



Available materials


To set up the lesson follow the links below and download all available materials.

Lesson plan download
Lecture download
Demonstration tutorial download
Scenes & Assets download

Lecture



1. Terminology

Lighting is important to our lives and scenes in 3D. Without it we can’t see anything!

  • Image Based Lighting
    • Using a texture/image to generate illumination in the scene
  • Color Temperature
    • A real-world measurement of the hue of a light
  • Subdivs
    • The quality of the soft shadows created by the light
  • High Dynamic Range Images
    • An image format that produces a wide span between light and dark values

 

2. Light


Light Temperature - Use the temperature value to create the right mood for your scene.

 


3. Image Based Lighting (Also known as IBL)


 

  • Uses the colors and brightness of a picture to illuminate a 3D scene
  • Typically created from a High Dynamic Range (HDR) panoramic image

 

 

4. HDR Image (Also known as HDR or HDRI)


  • Uses multiple exposures (or stops) of an environment from super bright to super dark
  • Captures a large range of brightness in the scene & compiles it into a High Dynamic Range file format (.hdr or .exr)
  • Commonly applied as a V-Ray Environment Override or on a V-Ray light dome
  • Often used with panoramics that are photos from multiple angles stitched into a single 360° map that can be placed on an environment sphere in the scene

 

 

5. Dome Light


a) Light Overview

  • Intensity Multiplier controls the strength of a light
  • Color vs. Temperature - Similar results but different ways to get there
  • Dome Spherical changes light from hemispherical dome to a full 360° sphere - Useful when mapping a 360° panoramic image
  • Shadows controls whether or not the light casts them in the scene
  • Texture - Core of IBL abilities
  • Photon Emission attributes used for scenes with caustics

 


b) Intensity, Color, Temperature
  • Mode: Color - the light’s color is directly specified by the Color value
  • Mode: Temperature - specifies the light color temperature in degrees Kelvin. Great for matching real world lights
  • Intensity MultiplMode: Colorier - defines the overall strength or brightness of the light

 

 

 

Color Mode: Color (with green Light Color)

Color Mode: Temperature (with Temperature value set to 1800)

 

c) Sampling

Subdivs – controls the number of samples V-Ray takes to compute the lighting

  • Lower values mean more noisy renders, but will render faster
  • Higher values produce smoother results but take more time to finish


Light cutoff threshold – specifies a threshold for the light intensity, below which the light will no longer be computed

  • Useful in scene with lots of lights, and you want to limit the effect of the lights to a distance around them
  • Larger values cut away more from the light; lower makes range longer

 

 

Subdivs: 2

Subdivs: 16

 


d) Shadows 

Shadows - light will or will not cast shadows

  • The majority of the render definition seen from a dome light is because of the shadows. If you turn them Off on a simple Colored light, all you will see in the render is that flat color over everything

Shadow bias - the Shadow bias moves the shadow toward or away from the shadow-casting object(s)

Shadow Color - controls the color of shadows for this light

  • Note that anything other than black is not physically correct

 

With Shadows

 

e) Texture

Use Dome Tex - tells the light to use a texture on its surface – This is useful for adding a panoramic HDR to the scene

Multiply By The Light Color - colors in the texture are multiplied by the color in the Light Color parameter

Dome Tex - specifies an environment texture map to use, commonly an HDRI

Dome Tex A – specifies an alpha texture for the dome light

  • Adjust Direction of the Dome Texture within the VRayPlaceEnvTex node/tab
  • Less interactive method of adjustment - Horizontal rotation value
  • Direct interaction within the viewport - Turn On Use transform to rotate with standard translation tools

 


Combining Texture and (No) Shadows
  • To make it clear that turning Off Shadows does not always create a black and white image, to the right is an example with our IBL set up

 


Please note that the detail seen in the render is from the color variation in the HDR image used in the Texture.


 

 


f) Viewport Display
  • Show in viewport - controls whether and how the texture is seen in the viewport
    • Disabled - the texture is not displayed
    • Texture only - the texture is displayed as it is
    • Texture*Intensity - the texture is multiplied by the light intensity before it's displayed
  • Hardware texture res. – specifies the resolution at which the texture will be previewed in the viewport
    • Sphere object detail – controls the number of faces used to display the sphere in the viewport
    • Convert to sRGB color space – automatically converts the environment texture to sRGB color space
    • Gamma – specifies a gamma value to be applied to the environment texture in the viewport

 

g) Options
  • Invisible – controls whether the shape of the light itself is visible in renders
  • Affect Diffuse - determines whether the light is affecting the diffuse properties of the materials
  • Affect Specular - determines whether the light is affecting the specular of the materials (this means glossy reflections)
  • Affect Reflections - determines whether the light will appear in reflections of materials (this means both perfect and glossy reflections)
  • Affect Alpha - determines whether or not the Dome Light will be visible in the Alpha channel
    • When Enabled, a white alpha is seen where the background is visible
  • Diffuse contribution - a multiplier for the effect of the light on the diffuse
  • Specular contribution - a multiplier for the effect of the light on the specular
 

Conclusion



a) Dome Light
  • Intensity, Color, Temperature
  • Sampling and Shadows
  • Dome Spherical

b) Textures
  • Using HDRs
  • Place Environment Tex

c) Options
  • Invisible                  
  • What To Affect or not to Affect

 

Demonstration



Time to see it work! 

Watch while I demonstrate how to create and adjust a Dome Light in our miniature house scene

 

      

 


Activity



Time to do it yourself!

Use the provided start scene file to recreate the cinematic look as you have seen me demonstrate.
We have also provided a final scene for your reference.

Values I used for your reference - Dome Spherical Texture.

 

  • Use Dome TexenvSea_D EXRPlaceEnvTex with Use transform to rotate dome direction

       Options
  • Invisible
  • Affect defaults   

Additional resources