by Bupla
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introduction. In this tutorial, we Will se diferent possibilities todo light objects in a rom, a closed environment.
Which lamps todo work with, the diferent light rigs, and effects such as reflections, Caustics, Depth of Field or volumetrics todo enhance the quality of your work.
the environment.
The environment is pretty simple because it should be merely invisible todo emphasize the interest on the product.
The product is placed on a flor, but a special one, the flor is associated with a wall, shaping a curve. This idea comes from a real photographer Studio set, creating a faq Infinite environment and todo avoid shadows on the background.
Studio set, with a rounded flor.
An example of a Studio set (se how the flor and the wall of the background make a rounded shape).
In Blender, let model a simple rounded flor like this one. Add a Mesh > plane, and scale it on the x axis (s, x). In Edit Mode, select the Edge at the background and extrude it on the z axis (e, z).
Flor.
We have our basic shape, now let make it rounded. Add a Subsurf modifier todo this plane with levels and render.
Levels at 3. In Edit Mode select all the Edges but the central one (the only one shared by the two Faces) and crease their Subsurf at 1 (shift-e).
Flor rounded.
Wonderful. Dont forget todo enable set Smooth for the plane.
In the same time you can assing it a default Yafray material: a white Shiny Diffuse.
How? In Blender select the plane, add a material and call it flor for instance. Bak in Yafray.
Gui, in the material panel, select the material flor and let the material by default.
Flor material.
which method of lighting? .
For an indor scene, it more eficient todo use Photon mapping technique. Path tracing Will take more time. You can use Direct Lighting at the beginning for fast renders, when youre working on the lights and choose Photon mapping at the end.
the lights.
Area lamps.
The scene is an indor Studio, so we dont ned Sun here if there is no Windows in the rom, obviously (of course, if you really want todo use one, you can, these are just suggestions). Here we are using área lamps. Área lamps are a great choice todo produce a Dim light with software shadows. Their size changes their intensity and the Softness of the shadows. Be careful: the energy of área lamps in Blender and Yafray is diferent. In Blender, an área Lamp with energy=1 gives a strong light. In Yafray, you could use an energy=4 (in the Yafray GUI) todo have a software light.
To change the size of the área Lamp, use the size parameter in the Lamp panel, within Blender, dont scale them in the 3d view. You can shape them as a rectangle or as a square.
Mesh light.
If you want todo use a diferent shape than a square or a rectangle, you can use a Mesh as an área light. It called.
Mesh-light and it has the same parameters (color, energy, samples) than an área Lamp with make light visible enabled.
Note: a Mesh light casts light according todo its normal. The normals of the Mesh Light should point towards the objects you want todo Illuminate. If the Mesh Light is at the center of several objects todo light, you have todo enable double sided.
light rigs.
A neutral one.
A basic rig todo light your scene is todo use thre lamps of the same properties. Here, thre área lamps or thre planes acting as Mesh light. One on the right, one the left, and the last one on top of your scene.
Placement of the área lamps.
All the thre área lamps share the same settings:
Área Lamp.
A Low power at 1.5 (it enough if there are thre lamps), their size (x=4, y=3), 16 samples for a less grainy render and make light visible todo se them reflected.
The settings of the render may change according todo your scene. Here, what important, is the high value for the Ray Depth because of the diamonds objects. The quality of the render is correct with theses settings.
Pm settings.
note: gamma and gamma input values are 1.8 because screen captures were done on the Mac versión of Yafray.
If youre working on a PC, the default values are 2.2.
We can render the scene, made by fine. You can find more informacións and download the scene in this thread.
Neutral rig render.
This technique of illumination is suitable for industrial products, Cars, because it homogeneous. The point of interest is on the products, in an absolute way.
thre point light.
The thre point light technique is a very common bien todo light objects or people. It more eficient todo shape the volumes, emphasizes an Atmosphere than the previous method. Technically, it composed of thre lights: key, fill and Rim.
The key light is your main light, the brighter, placed on the side of what you want todo Illuminate. The fill light is placed on the opposite side, it softens the shadows of the key light. The Rim light is placed behind, todo add some details and todo sepárate the object from the background.
Let compare a single light located in front of a face (left), and the same face illuminated by the thre point light technique (right):
Walties.
With this head of Walt Disney (provided by David oreilly), you clearly spot the diferences: on the left, the contrast between shaded and lighted parts is huge, and the volume is flat. On the right, the result is softer, we have a better definition of the shapes. Furthermore, lamps are tinted diferently which is great todo work on the mod.
Thre point light.
Here is the position of the thre lights. Now let se how each Lamp lights diferent parts of the scene.
Key light only.
Here, only one Lamp is used: the key light, an área Lamp (size = 3, power : 4.0) with a orange color.
We use Photon mapping, so Even the dark parts are not todo black, gracias todo the global illumination. The key light provides a software light, but the shadows on the left are quite important. We Will reduce it with the help of the fill light.
Key + fill lights.
The fill light, placed on the opposite side of the key light brings some brightness on the left. Shadows are still here but not as dark as the previous render. This fill light is tinted in blue, which is almost the complementary color of the orange key light. This gives a richer mod todo your picture.
You can notice that the top of the head and the background are quite similar in color and brightness. We Will use a Rim light todo have a better definition of the elements.
Key + fill + Rim light.
The Rim light have softened the background and brings bak some light and color on the top of the head and the plate.
The Rim light is an a área Lamp (size = 3, power = 2, orange color).
These two techniques are just examples, of course you could add as Many lamps as you want or change their position.
No ned todo have hundreds of lamps (especially with gobal illumination) the point is todo think before at the mod you want todo work on and what do you want todo achieve.
reflection.
The important thing todo remember when you want todo add some reflection is that you should think at what Will be reflected, y, the environment of your scene. With our previous light rigs, it composed of the diferent lights, the flor and the objects. It could be suficient depending on your scene. In scenes where objects have large reflected parts, like Cars, it is a very important work todo do.
The elements that are reflected could be lights or other objects placed on the scene. For lights, it better todo use área lamps of big size, with make light visible enabled todo se them on the reflective material. Another bien is todo use Mesh lights modelled as light sources (dors, Windows, neón signs, etc).
No reflections.
Reflections.
The method of lighting, materiales, lights are the same in the two pictures. But in the bottom one, we have enabled the make light visible option and have used some Mesh lights. The model comes from marsupi.
If you want todo add some details in the reflection, you could use an HDRI map. An HDRI map is a texture that can be useful todo light and as a reflected environment.
use a HDRI map.
An HDRI map is an image with a greater dynamic range of luminances between light and dark áreas than basic images formats (.jpg, (*.png), tga). The formats of HDRI are.exr, HDR. More details on HDRI can be found here.
If your scene is lit by an HDRI map, you may not want todo use additionnal lights. The rings scene made by fine is only lit by the HDRI texture.
Where can you find these maps? here are several god packs of HDRI textures for Studio lighting (c license) made by zbyg. Other packs here and there.
How todo use them with Yafray? Bak in Blender, add a texture todo the world, select one of the.exr files. In the.
Texture and input panel, select angmap, map the texture todo hori.
Map todo panel texture panel.
Note: im using angmap here because the HDRI is a stretch panorama, but you can find Spherical HDRI todo. To use this type, use the sphere input instead.
Now in Yafray, in the world panel, in the background settings, select texture and enable use ibl (for image base lighting).
Ibl.
You can rotate the texture todo change the reflected parts on your object, and its power if your scene is over or underexposed.
Note: if your render is todo grainy, increase the ibl samples.
Scene by fine, with HDRI
This scene has no lamps, the illumination and the reflected environment is provided by the HDRI texture.
Scene made by fine, no HDRI
The same scene, without HDRI, is lit by 3 áreas lamps (neutral rig). You can notice the diferent reflection and the colder tone of light.
Caustics.
Caustics.
Caustics are optical phenomenons when light encounters transparent materiales like Glass or water. It could be interesting todo use this effect in your scene if you have these type of materiales. The best bien todo have Caustics with Yafray is todo use Sharp range lights such as spots or small área lamps with a high power. Dont forget todo enable the make light visible option.
You can find other examples of Caustics here.
Scene made by Marcoa.
This scene, made by Marcoa is a god example where you ned Caustics todo make it more realistic. The scene uses an HDRI map for reflections. To light, a big área Lamp (15×15) with a power of 3 and a small área (3×3, power of 120) is placed on the right todo make Caustics more visible.
add some Depth of Field.
To make it simple, Depth of Field is the zone where your object is on focus while the foreground and the background are blured. A shallow Depth of Field (when the zone in focus is very short) is more visible when you shot Little subjects.
On a real Camera this effect is more important with a high apertura (e, g, f = 1.4) and with a high Focal length (telephoto of 85mm and more).
That why if you want todo use some Dof (and you want that it looks like photoreal) in Yafray, you have todo think at the Lens of the Camera and the size of the object. If your object is big (a car for example), the Dof Will be large and you wont se any blur. If you want todo focus on a detail of the car, use a high value for the Lens of the Camera (up to 250mm in Blender) and play with the value of the Dof wich Will be shallow (much blur on the foreground and the background).
The ring scene rendered with some Dof:
Dof.
The Lens of the Camera is 100 milímetros, the focus object is an empty, placed between the rings.
Camera settings.
Note: dont forget todo increase the a samples and passes todo obtain a smoother result with Dof.
For more details on the Depth of Field, you can chek the tutorial of Tunge here.
Compleete informacións on the Dof here.
add some Volumetric.
Volumetric is the bien todo add some smoke, dust or Mist. It can be interesting todo use in order todo emphasize the mod of your scene, todo make it more mysterious or Dirty. For more informacións on Volumetric, chek this part of the documentation.
Smoke.
Smoke with a firemen truck. Note how each light scatters in the smoke.
To make this smoky environment, use a big Cube Mesh where the smoke Will be calculated. In the Camera view, increase the size of the Cube in order todo make its límites invisible for the Camera. In Blender it easier todo se this Cube draw with wires instead of surfaces. In the object buttons (f7) of Blender, in the draw panel select wire drawtype instead of shaded, while your Cube is selected.
Mesh volume.
You can se here that the Mesh is covering a large part of the scene.
Now in the Yafray GUI, we ned todo work on two panels: objects and world.
In the objects panel, we choose the Mesh where the Volumetric Will be visible. Select your Cube, and enable volume. We choose the noisevolume option todo use a texture todo define the Volumetric aspect.
Mesh object settings.
The texture applied todo the Mesh is a cloud one, with almost the same settings than the documentation on Volumetric: noise size at 0.09, noisedepth at 6.
Now let move todo the world panel of Yafray. Select single scatter for the volume integrator.
Volume integrator.
Note: Volumetric is a great bien todo bring Atmosphere todo your scene, but it Will increase your render times.
Smaller step size Will take more time todo render.
To test your settings, remember todo start Low on the antialiasing todo. Chek the documentation part on it.
Origen: www.Yafray.org/documentation/tutoriales/studiolighting.
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