Introduction


This lesson will take you through converting a piece of geometry into a Mesh Light

The information centers around the use of the VrayLightMesh

This lesson topic is approximately 20 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 VRayLightMesh and understand how to adjust the settings to create the look you want in your renders


Contents


Overview
Available Materials
Lecture
Demonstration   
Activity                                                                                                                                                  
Additional resources


Overview


Goal - You will learn how to use the Mesh Light V-Ray Properties to turn any geometry into a direct light source.

Objective – We will light a scene with geometry converted to a light surface and understand how to adjust it to get the desired results.              

Outcome – You will know how to create a V-Ray Mesh Light from a piece of geometry in your scene.

 
 

 

Available materials


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

Lesson plan download
Presentation (Lecture) download
Demonstration tutorial download                                                          
Scenes & Assets download

 


Lecture



1. Terminology

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

  • Intensity
    • How strong the light will be in the scene
  • Color Temperature
    • A real-world measurement of the hue of a light
  • Shadows
    • Light isn’t just about where is shines but where it doesn’t

2. Light


  • Lighting in the real world
    • Lighting is also about creating shadows
    • Larger lights will have softer (more diffused) shadows
    • Lights with irregular shapes

 

 


  • Light Falloff
    • Real lights have Decay
  • Light falls off to the square of it’s distance – Inverse Square Law
    • An object at 2x the distance away from a light will receive 1/4x of the light it would at 1x distance
    • An object at 3x the distance away from a light will received 1/9x of the light it would at 1x the distance

 

 

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

 

 

3. Mesh light 


 a) Light Overview

  • Intensity is the overall strength of a light
    • The Units used affect if the amount of light emitted by the V-Ray light depends on its size
  • Color vs. Temperature
    • Which mode to use depends on what results you want
  • Texture
    • Allows for more detail or colors in the light than from the basic parameters

 

 

  • The VRayLightMesh allows you to create direct mesh based lighting in your scene
    • Allows you to create light sources that have volume and shape without the need to use self illuminated objects and global illumination
  • To convert a mesh to a light source you need to add the VRayLightMeshProperties node to it
    • Select the object(s)
    • Right click the Mesh Light button in the V-Ray Shelf and select the Turn selection into lights (apply single VRayLightMesh)

 

 

 

  • If the VRayLightMesh is close to other surfaces in the scene, it is best to use it with GI enabled
    • This will allow V-Ray to use combined direct and GI sampling of the mesh light for best results
    • Without GI, the light may produce noisy results for surfaces that are very close to it

 

 


b) Intensity – controls the brightness of the light. The value and effect depends on the Units p

Units – controls the “meaning” of the Intensity parameter

default – the Intensity parameter directly controls the intensity of the surface of the light source.  This means that a bigger light will emit more total light than a smaller light with the same Intensity

Watts (and Lumens) – the Intensity parameter controls the total amount of light coming from light source. This means that a smaller light will appear brighter than a bigger light with the same intensity, however they will both emit the same amount of light.

 

 

 

 

c) Color Mode – specifies how we control the color of the light

Light Color – we directly set the color of the light using an RGB value

Temperature – the color of the light is determined using the Temperature parameter

 

 

 

d) Texture

Use Texture - tells the light to use a texture for the light surface. If there are surfaces which are close to a texture-mapped light, it is best to have GI enabled. This allows V-Ray to use combined direct and indirect sampling for the light, reducing the noise for surfaces close to the light.

Texture - specifies the texture to use

 

 

 

 

 

Conclusion



  • Mesh Light

a) GI if needed

b) Intensity – default or Watts (Lumens)

c) Color – RGB or Temperature                                   

d) Texture


Demonstration



Time to see it work! 

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

Demonstration tutorial           

 



Activity



Time to do it yourself!

Use the provided scene file to recreate the cinematic look as you have seen me demonstrate

 

 

Used values:

  • Intensity Multiplier – 0.200
  • Units – Watts
  • Use Texture – enabled                             
  • Texture – Star_noise

Additional resources


Find more training resources listed below: