V-Ray Notes (Week 05)

We will explain four lighting sources in V-Ray:

1. Global Illumination

2. Sun System

3. Point light

4. rectangular light (there is also spotlight and other lights)

Getting Started

  1. In Rhino, type Sphere>specify center point at 0,0> specify radius at “x”
  2. Rename layer “Sphere”
  3. Create new layer, rename it “Infinite Plane,” double click to make current.
  4. In the V-Ray toolbar click the Add V-Ray Infinite Plane icon (similarly, you can type the command “visInfinitePlane”)
  5. The Infinite Plane allows our object to cast shadows onto a surface

Topic_01a: Global Illumination

  1. In the V-Ray toolbar click V-Ray Options icon, a window appears.
  2. In the top left corner of the window there are 5 icons (Save, Load, Load Defaults, Import, Export) click Load Defaults
  3. In the V-Ray Options window, look for the Camera tab, click to expand. Ensure Shutter Speed is set to “300.” Click the Camera tab again to collapse menu. (Lowering the number allows more light into the ‘camera’)
  4. In the V-Ray Options window, look for the Output tab, click to expand. Change the Output Size to “640×480” and click the Get View Aspect (Notice the output size has been altered to “640×325”)
  5. Close the V-Ray Options window. In the V-Ray toolbar, click the Render icon to start render. Two windows pop up, one is the “V-Ray Progress” window (shows the status of current render), the other is the “V-Ray Frame Buffer” window (shows the actual render)
  6. When render is complete, In the V-Ray Frame Buffer window, click the Save icon in the top of the window.

Topic_01b: Sun System

  1. Create new layer and rename it “Sun,” double click to make current.
  2. In the V-Ray toolbar click Add Sunlight System icon, a window appears
  3. Ensure On and Manual Control are both checked
  4. In the Sun Position tab, adjust the Azimuth angle and Altitude angle by either manually entering a new number in the corresponding dialog boxes or moving the ball in the images in the left
  5. ***Both are linked, don’t worry about this too much but in short, time of day will affect the color and direction of light and shadow
  6. Click Okay
  7. Place the Sun anywhere near your sphere
  8. Open V-Ray Options>scroll to “Environment“> “GI (skylight)” >uncheck to turn off global illumination (because we are providing a sun)
  9. Click Render
  10. Notice the sharp edges of the shadows being cast. In real-life we know shadows tend to be more gradual and softer.
  11. Select the Sun>Go to the Properties tab near “Layers” tab.
  12. In the top of the tab there are 3 icons. (Object, Material, Light) Click Light
  13. Change Shadow Subdivisions from 8 to “30” (Notice how you can also alter other sun properties here; i.e. Sun size, intensity, turbidity)
  14. Test…Click Render
  15. V-Ray by default is also rendering with a black sky. You can change this by opening V-Ray Options>Environment>Reflection/Refraction (background)>clicking on the “m
  16. The V-Ray texture editor sets to “None” by default>Click and select “Tex Sky” from drop down menu. (click preview)
  17. RENDER…you should see a sky now.

*****If familiar with photography, these settings should be recognizable: Shutter Speed = Length of time that shutter is open and F-Number = Aperture or diameter of opening that allows light in. Both are ratios of 1/x so if shutter speed is 600, the shutter is open for 1/600th of a second (less light in) Or if it is set to 30, the shutter is open for 1/30th of second (more light in). Similarly if the f-number is set to 16, the diameter of aperture is 1/16 (letting less light in) and if it is set to 4, the diameter is 1/4 (more light in) Both setting regulate how bright/dark image is.

Topic_02: Rhino Lights (Rectangular/Point Lights)

1. Make a new layer, label “Rhino Lights”

2. Turn off sun layer, or delete layer

3. Make Rectangular Light  (you can mirror the direction, line points in direction of light)

4. Open up V-Ray Options>In top toolbar, select restore/load defaults

5. In Camera tab, turn off or use default camera (Play with controlling light more, shutter speed, etc)

6. In Environment tab>GI (skylight) turn “m” off> Render

7. Right click over “Rhino Lights” layer>Select Objects (Your light should be highlighted)

8. Open Properties Tab (Next to layers)>There are three icons located here>Click “Light”

9. In “Decay” select Linear. Also scroll down and change shadow subdivisions from 8 to 30

10. Set Multiplier to 2

11. Move the light source closer, and above right

12. Render

Point Light

Make point light, top right

decay, leave on “linear”

you can check on and off “Light”

Topic 3. Material Properties (from download)

VRAY, Material editor

Change default material to red, select object,

rename “red_ball” right click “apply material to objects”

*render

Vray will reflect light and color

+ sign, the order will affect them, will need transparency at top

Emissive is giving off light

Reflection

Diffuse is color and matte

Refractions is refracting layers

…add reflection, Add new layer

Reflection, I use the default

*test

you can change settings in “m”

fresnal- look from angle

refraction- look straight on

shade of grey will affect, darker grey, makes it duller

*leave on default reflection

to make transparent

“diffuse” layer/ light grey is more transparent

test with dark grey (light starts to go through it)

Right click, Add Material, add VRAY MATERIAL

Copy ball

Rename “purple_ball”

VRAY has default materials/ Import new materials

(you will be directed)

make new material

“clear_glass”

Mapping Materials (wood)

**if you download a material, make a new folder and put it in its own folder along with any associated files that came with it. ORGANIZE!!!

1. Click V-Ray Material Editor (M Icon on top toolbar); a window appears

2. On the left hand column, right click on Scene Materials>Load Material>locate the file (wood material from AAA Server), load into library. Check “live update”>(you should see a preview of material in sphere)

3. Notice on the right side of the window there are 4 drop down menus labeled: Reflection, Diffuse, Options, Maps (Adjusting these parameters allows you more options in controlling the reflection properties as well as emissive qualities within a material.)

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