The VRayLightMtl is a special material provided with the V-Ray renderer. This material is generally used for producing self-illuminated surfaces.
General
Color - this parameter controls the color of the light material.
Color multiplier - a multiplier for the Color.
Section
border
true
Column
width
100%
Info
Anchor
Examples
Examples
Example: Default Color and Multiplier Values
Here is a scene rendered with the default VRayLightMtl. These examples demonstrate how the material behaves in V-Ray, and how its parameters influence the look of the final results.
Section
Column
width
25%
The white plane is a default VRayLightMtl. The teapot is a default VRayMtl with Reflection. The rest is just VRayMtl with diffuse colors.
We are going to render this scene with Default Lights turned off until the endof the example, and no lights will be used in it either.
Column
width
25%
Default Lights - Off. Multiplier: 1.0 No GI, No lights
As you see, the image is absolutely dark except the plane (self-illuminated) and the reflection on the teapot. Notice we have no GI and no lights at all here, so the dark part of the scene is to be expected.
Column
width
25%
Multiplier: 50.0 No GI, No lights
Notice that nothing changed in general, BUT the reflection on the teapot got stronger due to higher multiplier. The rest is still black because we still have the GIoff.
Column
width
25%
Multiplier: 1.0 GI: on
As you can see, turning GIon almost didn't change the overall look. That is because of the Multiplier value: 1.0. It acts mainly to self-illuminate the object that has the VRayLightMtl.
Section
Column
width
25%
Multiplier: 5.0 GI: on 2-sided: off
Now you can see that increasing the Multiplier has visibly influenced the scene (shadows also appears).
Column
width
25%
Multiplier: 5.0 GI: on 2-sided: on
Scene starting to gather more light because 2-sided is on.
Column
width
25%
Multiplier: 10.0 GI: on 2-sided: off
As you can see, the back is still dark, but you can already notice the blue wall receiving some GI, due to a higher Multiplier. Shadows also appears more defined.
Column
width
25%
Multiplier: 10.0 GI: on 2-sided: on
The scene starts to gather more light because 2-sided is on, but we also start to get some burnt areas due to LineartypeofColor mapping
Section
Column
width
25%
Multiplier: 30.0 GI: on - default 2-sided: off Exponential
So, increasing the Multiplieraffects the GI more (we have more light), but you can also see that our render is quite splotchy.
Column
width
25%
Multiplier: 30.0 GI: on - default 2-sided: on Exponential
Scene starting to gather more light because 2-sided is on. Still splotchy GI solution.
Comparing this result to the previous, the new render looks much better. The GIsolution is clearer, and shadows are more precise. Of course, this leads to higher render time.
Comparing this result to the previous, the new render looks much better. GIsolution is clearer, and shadows are more precise. Of course, this leads to higher render time.
Section
border
true
Column
width
100%
Info
Example: Texture as Color
This example shows how the Texmapslot is used and how the map determines the Colorparameter.
Increasing the Multiplier leads to a much brighter look in the scene. Notice now that the Bitmap is getting closer to appearing white, due to multiplying the (R,G,B) values of the Bitmap.
Here, another Bitmap is assigned to the Texmap slot. Notice that we haven't changed the VRayMtls for the surrounding walls, but the scene looks different from the previous one due to the new Bitmap.
Increasing the Multiplier leads to a much brighter look in the scene. Notice now the Bitmap is getting closer to appearing white, due to multiplying the (R,G,B) values of the Bitmap.
Section
border
true
Column
width
100%
Transparency - a color or texture to use as opacity for the material. Note that making the material less opaque does not affect the intensity of the self-illumination color. This is so that you can create perfectly transparent materials that nevertheless still emit light.
Emit on back side- checking this option makes the object emit light from its back side as well. If this is off, the material is rendered as black on the back sides.
Compensate Exposure - this option is used when rendering with the V-Ray Physical Camera. When enabled the intensity of the material will be adjusted to compensate for the camera exposure.
You can use the VRayLightMtl as a light source assigned to an object. Increasing the Value of the color will affect the GI solution and will produce more light. Note that over bright colors may look the same as pure white but the GI results will be different.
