Maya Lighting Tips and Tricks

-For VFX Artists, Lighters, or Rendering Artists.

Lets Start with Lights: 

Spot Light:  This light casts light in a cone shape. It includes modifiers such as: Color, Intensity, Emit Specular,Decay Rate, Cone Angle, Perumbra Angle(softness of the edge of the light), Drop-off(Light intensity falloff)

Point light: This source is supposed to replicate a light bulb in the room of your scene. The light will illuminate in all directions from the point source. Has no cone angle or Penumbra.

Directional Light: This source acts like a spot light, but it evenly illuminates the scene. This is the best type of light for sunlight. The shadows from this light source will change with the direction of the light. Depth map shadows do don't work with this source.

Area Light: Replicates light as if it was from a soft box. You can increase the intensity of this light source by either scaling the light, or manually increasing the intensity.  Keep in mind that scaling the light will increase the sharpness of the light source, and move it closer to the object. This source is also directional.

Ambient Light: This creates bounce lighting in the room. The shadows from this light source will not be completely black, and this source will create a wash of light. This light works best in a combination with other lights. If you were to add other lights +/or an ambient light the room will never be completely dark, as ambient lights increases the overall light in the room.

Skydome Light: (HDRIs insert these here) Used for photo realistic rendering. Also used for lighting interior scenes. If you are plugging in an HDRI into this light source make sure you change its color space to RAW. Remember to adjust only the exposure on this light for the best results.

 Light Portal:  Reduces noise in interior scenes, and also is used for areas where light comes through. Such as from doors, windows, etc. This source will also increase the light bounce in the scene. Always position this light source over the windows/doors, and always make them slightly bigger than the opening. There are options on this light for exterior and interior-only. If there are multiple windows and doors in your scene, make sure you create a light portal for each one. 

Mesh Light: This source will turn any object into a light. Select the OBJ, and under it's attributes go to the Arnold tab, and change Arnold translator from poly-mesh. to light mesh. Adding an exposure of 8 or more keeps the light visible. Keep in mind the mesh lights ignore smoothing on your meshes.

When lighting a scene there should always be a few things you should look out for. No matter what you are creating, you need it to be convincing when you render it out. Here are some pointers.

  • Make sure you have a lot of lighting references. When you can match the lighting that you would like to create with something else, you are going to have an easier time creating your lighting. Ask yourself: what are the brightest parts of the scene? What are the darkest? Where is the direction of the light coming from? Then base these question off of your reference, and created scene.

  • Make sure that the models in your scene are up to standard, or will work well with the lighting. If your models have sharp edges, or have thin geometry, then the light will not bounce correctly off of them. Also, if your models do not accurately represent the objects in the scene they will never look correct. For example, if you have a building modeled in your scene, and the walls of the building are thin and flexible, then the model building will never look right with the lighting. Buildings are tall and sturdy. Make sure your models are too.

 

  • Make sure your Shaders are natural, and fit your scene.Make sure that the colors of your shaders are balanced, and will respond to your light sources correctly. Make sure the colors of your shaders are not clipping into the blacks or the whites, the saturation is off balance, or the hue color is off. Otherwise, the RGB balance of your scene will always be wrong. I talk more about color correction in my Davince Resolve article, but most of the concepts also apply here. Check out the article HERE. A good range to keep your  RGB balance of your shader is between 0.2 and 0.8(when on a scale from 0 to 1). 

  •  Make sure there is Spill lighting in your scene. Without spill lighting, your scene will look dark and unclear. It will also give your scene the feeling of warmth and extend illumination around your objects. Just make sure your spill lighting is less intense than your main source of light in your scene. Spill lighting can be considered a form of indirect lighting. 

  • Divide the Areas of the scene into interesting lighted areas. Sometimes having lighting that directs the viewer's attention into a certain area will carry weight in your scene. For example, horror movies. Almost in every horror movie there is a dark room with singular light sources that tell the viewer or the character to head in that direction. This type of lighting is an effective part of telling the story of the scene. This method can also be applied for different colored lighting, and warmer or cooler lighting. If your scene is transitioning from a hot summer beach scene to a colder igloo scene, you need the lighting to tell the viewer that these scenes are different.  However, even with regular scene such as a room, keep in mind that the intensity of the light will have a falloff point. Lights will be brighter and harsher around windows or doors, while in the corners of the room they will be less direct, and more soft.

  •  Play with the position of the light. If the light is closer to the camera, the foreground of the shot will look brighter, and the background darker. And vise versa. Viewers expect the more distant parts of the scene to have reduced contrast and saturation, as distant objects are harder to see. Plus they may be obscured by dust, fog, etc. Therefore, you can also consider adding atmospheric lighting to your scene. There should always be some difference in lighting between nearby and far away objects.

  • Remember to add bounce lighting! Global Illumination is an important part for creating bounce lighting, but sometimes you'll need more than just a simple GI light. Sometimes in certain areas of your scene you'll need extra bounce lighting, just so the colors and appearance of the scene looks real. If there are characters in your scene considering making the bounce lighting a warm tone so the lighting matches their skin colors. Remember that the darkest parts of your scenes will have the most saturated colors. Be careful with your bounce lighting in this case as you can quickly make these darker zones grey and uninteresting. If you have a red rug in your scene, consider making your bounce lighting red to amplify the red tones. 

  •   Watch the way the light interacts with the character's eyes. Eyes communicate the emotion of the character, so it is important to make sure this emotion is visible. Also remember that the eyes also create depth in the character's face. Wherever the eyes of the character is facing is where the light will enter. These will create iris glints. (Scooping) Without these eye highlights, the character will not look alive. Highlights in the lower end of the eye will make the character look like it is crying. 

Some Other Lighting, and Rendering Pointers in Maya

  • Hit 6 on your keyboard to see the textures in your scene. This is the hotkey for it.

  • The hotkey for viewing the lighting in your scene is 7. Otherwise everything will look black.

  • Make sure all your reference for everything(not just your lighting) is in one place. Therefore, it will be easier to switch back and forth from your scene to your references.

  • If a GPU RAM error appears. This is probably a texture issue. You'll need to set a texture clamp on them from either 1080 or 512. If the error still persists, then make sure the Project is set correctly, and the file paths are correct.

  •  In an indoor scene the key light of the room might be a window or a door. In this case the key light source would be the sunlight.

  • If you need a warm sunlight, turn shadows on. However, in some cases you might have to use a spot light instead of a directional light for the sun. A spot light will create sharper and tighter shadows. This might be useful for scenes where you would like to define the shadows more.

  •  If you are having trouble creating nice shadows. Try turning depth map shadows on. If you would like sharp shadows, set the resolution to 4096, and a filter size of 3. For softer shadows, lower the resolution. But this might cause a flickering effect.

  •  If your renders in Maya look washed out, and colorless. This is because of Maya's Linear workflow SRGB Gamma setup. This workflow only calculates how the light and surface colors react to each other. Therefore, viewing the full range of color in your scene will be fairly hard to do. You'll need to preview the color setup of your scene. If you work in a studio, ask the lighting department about this. If you are working by yourself, all you need to do is go to preferences, and chose acesCG color work space and RRT 1.0 as the display transform option. Always do this change before you start making changes to a scene, or when you are first creating the scene. 

  •  For HDRIs , you can download them from the internet, or find them in the Maya install folder. Sometimes HDRIs can make the performance of your scene slower. So sometimes you'll have to same out your HDRI as a lower resolution, and then reload it into your scene.

  • You'll need to activate the shadows in the sky dome light to have a realistic look. Enable SSAO in the veiwport to see these shadows.

  • You can also create back lighting for your characters to define them more. Add a directional light and turn it away from the key light. This will create rim lighting in the scene.

  • Check the resolution gate in the veiwport to see what the final output will be like in the play blast. Ten disable it when you are finished to make sure it is not included in the render.

  •  If aliasing or weird edging is occurring with your render, go to the veiwport settings and turn  MSAA.(multi-sample anti aliasing). However this might use up a lot of your GPU RAM. To prevent this , lower your texture RAM,  or disable depth peeling transparency.