Understanding Lights in Maya Part 1: Ambient Light & Directional Light

Step 1

Before starting anything make sure your Mental ray plug-in is load up, if not then follow the images below.

Step 2

Keep Going

Step 3

Now from render settings, change the renderer (from Maya default to Mental ray)

Step 4

Ok now create plane with sphere to work with while testing lights, and then apply blinn material with any texture you wish and then do the following settings

Step 5

Now hit render without any light setup, and you should see something like this...

Ambient Light: step 1

It's time to drop light in the scene...

Ambient Light: step 2

Once the light created in the scene, Move it up on the top of your object, and then hit CTRL+A to bring Attributes Editor or in the other words to brings it's parameters

Color = this is the color of your light you could change the color of your light to any color you like,

Intensity = this controls the amount of your light, more values the brighter result and lower value the darker result,

Illuminates By Default = with this option you could ON and OFF the light,

Ambient Shade = I don't think you will need to play with it, the default value is 4.50 keep as it is, if you want to play please feel free, by increasing the value you will have a bit soft and darker light,

Shadows = its pretty self explanatory, if you change the color you will have the same shadow color you gave in the color chooser,

Use Raytrace Shadows = if you check this out your object will start casting shadows and this works nice with Mental ray,

Shadow Radius = this will soften the edges of your shadows,

Shadow rays and Ray Depth Limit = works almost together these could help you to achieve smoother shadows result

Ambient Light: step 3

In the render settings do the same settings as shown in the below image

Global Illumination is dealing with indirect illumination, specially works fine with photons, we will talk about photons in the Part 3 of these tutorials.

Ambient Light: step 4

Last but not the least still in the render settings check (Final Gathering) this option will help us to illuminate more and to get overall smoother result of our final output.

Ambient Light: step 5

Here is the final result with the same settings we did...

Note: These kind of lights are used to fill the scene, these lights usually called (Fill Light)
This was the end of first light, next we will start working on Directional light

Directional Light: step 1

As before create Directional Light

Directional Light: step 2

And place it somewhere on the scene

Directional Light: step 3

Hit CTRL+A to bring attributes editor for the directional light, if you see its a bit different then Ambient light, ok lets reveal what they are..

As we already had the chance to talk about (Illuminate by Default, Color, Intensity, Shadow Color) in the Ambient light settings, so we will talk about other settings

Emit Diffuse = if you have diffuse material in the scene and you don't want to show it you could simply uncheck it,

Emit Specular = same as diffuse if you have Specular materials in your objects by unchecking it wont show in the final render,

Use Depth Map Shadows = by checking this you will tell the system to cast shadows,

Resolution = the higher values the smoother result but longer rendering time, by default its 512,

Filter Size = will help you to smooth the edges of your shadows,

Bias = will increase the softness,and the rest just keep playing with the values you will understand what they dose, here i am just focusing on the main options.

Directional Light: step 4

By these settings now just hit render and you will get below image

Directional Light: step 5

As you see the shadows are too dark because we don't have any fill lights in the scene that is why they are looking too dark, for the sake of these tutorials we will just keep focusing on one single light to see the result of our changes.

You could also increase the shadow color to see the changes, but you won't make any difference except little bit change.

Directional Light: step 6

Now uncheck the Use Depth Map Shadows and scroll down to bottom and check (Use Raytrace Shadows),

Light Angle = will help you to smooth out shadows around the edges of objects,

Shadow Rays and Ray depth Limit = will help you to remove noise from your shadows, this works conjunction with Raytracing in the render settings as you will see next

Directional Light: step 7

open up (Render Settings) and then expand the (Anti Aliasing Quality) tab,

Max Sample Level = this setting will help you to get rid of jagged edges, if you render your scene and you could see that your objects looking jagged this is the option where you could control it out, well don't crank it up more then 3 otherwise you will compensate with huge rendering time.

Raytracing = this works fine with (Raytrace Shadows) crank up the values to the end and will help you to remove noise from your shadows.

Directional Light: step 8

Hit render, and you will see little bit smoother result

Directional Light: step 9

ok its time to final adjustment in the light settings, open up Render Settings and scroll down to bottom expand the Final Gathering tab just check (Final Gathering) and increase the (Point Density) to 2.

Directional Light: step 10

Hit the render button to see the result, Here i come up with the same settings we did.

Closing words & Links

Ok guys I hope this could help you to understand something about lights in Maya, in the part 2 of this tutorial series will explore about (Point Light) and (Spot Light).

You can find the Maya Scene file here: directional light sample scene

You can find other pats of this sereis here:
Part 2: Understanding Lights in Maya Part 2: Point Light & Spot Light

Part 3: Understanding Lights in Maya Part 3: Area light & Volume Light

Part 4: Understanding Lights in Maya Part 4: Interior Lighting