Rhino 6 and newer - Maxwell Lights

This section describes how to add different light types to your scene like area lights, spotlights, IES, projectors, etc. If you are looking for information about environment lights, like the Physical Sky, Constant Dome or Image Based Lighting (HDR), please check this section: Maxwell Environment.

There are two ways of adding lights to your Rhino scene:

Using native Rhino lights, along with some custom Maxwell options.
Using light-emitting materials applied to objects in the scene.

Native Rhino Lights

Maxwell will translate all the native Rhino emitters except for the directional light (which doesn’t have a match in Maxwell).

Maxwell will take into account the color and intensity of the Rhino lights but you will find some Maxwell-specific properties in the Maxwell section of the Properties panel.

The point, rectangular and linear lights can be set to Maxwell area lights or Maxwell HDRI lights. The Rhino spotlight can be set to Maxwell IES light or Maxwell spot and project light

POINT LIGHT

The plugin will translate it into a sphere and use it to emit light.

The following table describes the different modes available for a Point light:

Point light

Point light
By Rhino		As Maxwell area light.		As Maxwell HDRI light.
Multilight group	In this box you can type any text you like. All the lights sharing the same group name will be handled in Multilight with the same common slider that will work as a multiplier of the units of each individual light.
Light Type	Here you can choose how the plugin will handle the light. By Rhino is the default mode, but you can also turn it into a Maxwell area light to be able to set the color or the units with more precision or a Maxwell HDRI light to be able to emit light using an image (it is strongly suggested to use 32-bit images to get a richer light).
Diameter (cm)	It lets you set the diameter of the sphere in centimeters.
Segments	It lets you make the geometry of the sphere more or less detailed. Please, note that the emitters with fewer polygons render faster so, if the sphere is not going to be visible, it’s better to use smaller numbers.
Intensity Multiplier	It lets you increase or decrease the light intensity. 1 is translated to 100 cd.	Color / Temp.(K)	If the checkbox is active, it will use the custom color chip. If it’s deactivated, the plugin will use the K temperature color box on the right side.	HDRI File	Here you can set the file that will be used to emit light. It is strongly suggested to use 32-bit images, although this is not mandatory and you can load LDR images too.
		Light intensity units	It lets you choose between Power & Efficacy, Lumen, Lux, Candela and Luminance	Rotate Texture (º)	It rotates the texture in degrees in the UV space. Normally, the texture will be mapped to the sphere with a spherical map with one pole at the top and one at the bottom.
		Output	Here you can set the intensity value of the light. It may differ depending on the unit chosen above.	Tile X / Tile Y	Here you can set the times the texture is repeated horizontally (X) or vertically (Y).
				Rotation around axis (º)	This rotates the texture around the vertical axis of the sphere as rotating the point light doesn’t change the orientation of the texture.
				Intensity Multiplier	It lets you increase or decrease the amount of light emitted by the texture.

RECTANGULAR LIGHT

The plugin will translate it to an area light of the same side of the rectangular light that emits light in the direction indicated by the gizmo.

Rectangular light

Rectangular light
By Rhino		As Maxwell area light.		As Maxwell HDRI light.
Multilight group	In this box you can type any text you like. All the lights sharing the same group name will be handled in Multilight with the same common slider that will work as a multiplier of the units of each individual light.
Light Type	Here you can choose how the plugin will handle the light. By Rhino is the default mode, but you can also turn it into a Maxwell area light to be able to set the color or the units with more precision or a Maxwell HDRI light to be able to emit light using an image (it is strongly suggested to use 32-bit images to get a richer light).
Intensity Multiplier	It lets you increase or decrease the light intensity. 1 is translated to 100 cd.	Color / Temp.(K)	If the checkbox is active, it will use the custom color chip. If it’s deactivated, the plugin will use the K temperature color box on the right side.	HDRI File	Here you can set the file that will be used to emit light. It is strongly suggested to use 32-bit images, although this is not mandatory and you can load LDR images too.
		Light intensity units	It lets you choose between Power & Efficacy, Lumen, Lux, Candela and Luminance	Rotate Texture (º)	It rotates the texture in degrees in the UV space. Normally, the texture will be mapped to the rectangle with a planar map so it fills the whole area, taking the first line you draw when creating the line as the bottom side of the texture.
		Output	Here you can set the intensity value of the light. It may differ depending on the unit chosen above.	Tile X / Tile Y	Here you can set the times the texture is repeated horizontally (X) or vertically (Y).
				Intensity Multiplier	It lets you increase or decrease the amount of light emitted by the texture.

LINEAR LIGHT

The plugin will translate this light into a cylinder of the same length and diameter as the linear light gizmo (its maximum diameter is 2.5cm). The cylinder’s base has 8 sides (so it’s actually a prism).

Linear light

Linear light
By Rhino		As Maxwell area light.		As Maxwell HDRI light.
Multilight group	In this box you can type any text you like. All the lights sharing the same group name will be handled in Multilight with the same common slider that will work as a multiplier of the units of each individual light.
Light Type	Here you can choose how the plugin will handle the light. By Rhino is the default mode, but you can also turn it into a Maxwell area light to be able to set the color or the units with more precision or a Maxwell HDRI light to be able to emit light using an image (it is strongly suggested to use 32-bit images to get a richer light).
Intensity Multiplier	It lets you increase or decrease the light intensity. 1 is translated to 100 cd.	Color / Temp.(K)	If the checkbox is active, it will use the custom color chip. If it’s deactivated, the plugin will use the K temperature color box on the right side.	HDRI File	Here you can set the file that will be used to emit light. It is strongly suggested to use 32-bit images, although this is not mandatory and you can load LDR images too.
		Light intensity units	It lets you choose between Power & Efficacy, Lumen, Lux, Candela and Luminance	Rotate Texture (º)	It rotates the texture in degrees in the UV space. Normally, the texture will be mapped to the rectangle with a planar map so it fills the whole area, taking the first line you draw when creating the line as the bottom side of the texture.
		Output	Here you can set the intensity value of the light. It may differ depending on the unit chosen above.	Tile X / Tile Y	Here you can set the times the texture is repeated horizontally (X) or vertically (Y).
				Rotation around axis (º)	This rotates the texture around the axis of the cylinder.
				Intensity Multiplier	It lets you increase or decrease the amount of light emitted by the texture.

SPOTLIGHT

The plugin can translate this light into a Maxwell spot and projector light or into a Maxwell IES light.

Spotlight

Spotlight
By Rhino		As a Maxwell spot and projector light.		As a Maxwell IES light.
Multilight group	In this box you can type any text you like. All the lights sharing the same group name will be handled in Multilight with the same common slider that will work as a multiplier of the units of each individual light.
Light Type	Here you can choose how the plugin will handle the light. By Rhino is the default mode, but you can also turn it into a Maxwell area light to be able to set the color or the units with more precision or a Maxwell HDRI light to be able to emit light using an image (it is strongly suggested to use 32-bit images to get a richer light).
Intensity Multiplier	It lets you increase or decrease the light intensity. 1 is translated to 100 cd.	Bitmap File	If this is left blank, the spotlight will work as a normal spot; if you enter an image here, it will instead work as an image projector. It is strongly suggested to use 32-bit images, although this is not mandatory and you can load LDR images too.	Diameter (cm)	Maxwell internally applies the light distribution of the IES file to a low-poly sphere of 5cm in diameter. If you are placing the light in a smaller place, you may see some black areas (the inside of the sphere). This parameter lets you make that sphere smaller or bigger (bigger could be faster for rendering).
		Rotation around axis(º)	It lets you rotate the projected image around the axis of the spotlight. If there’s no bitmap, this parameter will have no effect.	IES File	Here you can set the IES or LDT file that will be used to emit light. If nothing is entered here, the light will work as a normal spot.
		Falloff Type	It lets you set different curve types to describe the way the light fades from the full intensity inner cone to 0 intensity outer one.	Rotation around axis(º)	It rotates the pattern of the IES file around the axis of the spotlight.
		Blur	It lets you make the shadows generated by the spot softer. In the case of the projector, it also blurs the projected image.	Intensity Multiplier	It lets you multiply the value of the IES file. 1 will output the intensity described in the IES file.
		Color / Temp.(K)	If the checkbox is active, it will use the custom color chip. If it’s deactivated, the plugin will use the K temperature color box on the right side.	Color / Temp.(K)	If the checkbox is active, it will use the custom color chip. If it’s deactivated, the plugin will use the K temperature color box on the right side.
		Light intensity units	It lets you choose between Power & Efficacy, Lumen, Lux, Candela and Luminance
		Output	Here you can set the intensity value of the light. It may differ depending on the unit chosen above.

Using light-emitting materials with custom objects.

The easiest way of creating a light-emitting material is using this button from the Materials toolbar:

Materials toolbar

The Maxwell Material has an “emitter” component that you can add to any material. That will make the object emit light in different ways depending on the emitter type. You can learn more about the different types here: Lighting with Emitters.

If you right-click on a layer or bsdf component, you will be able to add an emitter component to any material. Only one emitter component is allowed per layer.

It makes sense to add an emitter component to a normal material as, if you turn off the emitter in Multilight, the material will show up, otherwise, it will look black. For example, if you create a white plastic material and add an emitter component to it, you could simulate a white bulb; when you turn off the light, the white plastic material will show.

The interface of the emitter component resembles the general interface in Maxwell, but there are some particularities to take into account:

The area light type will only emit light from one side of the geometry, in the direction of the normal of the surface.
When you apply an emitter in spot or IES mode, the geometry will internally be replaced at render time with a procedural geometry in order to create the spot, IES effect or projector effect. It will point down by default.
The light types that need “directionality” in order to point the light in different directions, like the IES, spots or projectors, have to be included into a block so that you can orientate them. It is usually more intuitive to use native Rhino spotlights if you want to point them in a particular direction and activate their Maxwell options so they work as a spot, projector or IES light.

A particularity of the IES emitter

In the case of the IES emitters, the geometry to which they are applied is replaced at render time with a low-poly sphere of 5cm of diameter. If it is very close to a surface, you may see a dark area in the center of the object; that’s the inside of that sphere.

IES emitter problem. Are you getting this?

How can we avoid this? In this case, it is recommended to apply the IES emitter to a cube of 5cm in size or a sphere of 5cm in diameter (in order to get an idea of the size of the dark area) and then create a block from this object.

Once you have that block created, you will be able to rotate the IES light and, what’s more important in this case, to scale down the IES inner sphere without affecting the light distribution. This is the way of avoiding the black area in the middle.

After that, you can create a bigger block that includes the IES block and the light fixture, for instance.

I cannot see the effect of the light. Why my light doesn’t illuminate?

First of all, the scale of the scene is very important. Very big lights require very powerful lights and/or a very sensitive camera. The first thing you can try is going to the Properties panel with nothing selected to see the camera settings and lower down the exposure value (EV); this will increase the sensitivity of the camera. Also, a very big light (several square meters) will require many lumens to be visible unless you are using luxes or luminance units (which depend on the size of the emitter).

Also, there’s a big power difference between environment lights (for example, the Physical Sky) and spots, area lights, etc. You can turn off the environment to see what’s happening with your lights (set it to “None”).