LightWave surfaces with the node editor

The nodal surfaces in LightWave are pretty neat and allow for some complex surfaces to be made. Surfacing like this is still quite new to me so I am going to start documenting the node set up for some surfaces here on this page. There probably will not be too many surfaces here (not enough time for 3D!) but I will add to it from time to time.

Ambient Occlusion with Diffuse Texture

Here is a set up for Ambient Occlusion that can be mixed with a user specified diffuse texture:

Ambient Occlusion with Diffuse Texture

NodePurpose
Scalar - Base DiffuseBase diffuse value for the surface
Scalar Layer - Diffuse TextureTexture layer to control the diffuse value for the surface; layer opacity blends with the base diffuse value exactly like the old Layers based surfacing.
OcclusionAmbient occlusion node that calculates the occlusion for the surface geometry.
Scalar - WWeight of the ambient occlusion effect. This has range [0,1]. When W = 1, then the ambient occlusion effect is strongest.
Subtract(1)Performs (1 - W)
Multiply(2)W * Occlusion
Add(2)W * Occlusion + (1 - W)
Multiply(1)Produces final diffuse value:
[W * Occlusion + (1 - W)] * (Diffuse Texture Layer)

The effect of W is to set a minimum value (1 - W) that the ambient occlusion produces. Thus, the larger the weight W, the larger the effect of the ambient occlusion. Changing the weight W allows control of the ambient occlusion amount. Note that it seems that all the scalars output values between [0,1].

Subsurface scattering

For the compact fluorescent elight bulb modeling tutorial, I investigated using the subsurface scattering (SSS) node for making the light bulb tube translucent:

Lightbulb tube surfacing

I found out that the SSS node does not work very well with point or distant lights. I set up the scene with a few area lights, at least one of which is behind the object for a subtle translucency effect:

Scene setup for subsurface scattering (SSS) nodes using area lights

Here is the nodes setup:

SSS and Lambertian nodes mixed together for CFL phosphor surface

Settings for each node:

SSS node settings

Lambertian node settings

I mixed both Lambertian and SSS nodes for the diffuse shading. Scale(1) is set to 50% and Scale(2) is set to 100%. This controls the relative mixing of the two surface types.

Discussion

Darrick, 2012/10/27 13:23
Thank you so much.

I had been trying to learn how to combine SSS with other diffuse nodes. Your awesome tip about using a vector scalar really made things click.

Thanks again!

-Darrick
Jos, 2013/01/28 06:07
I have never seemed to understand all of the node stuff (and still don't...) but somehow this seems to work great to add AO to my materials :) so thank you!! and who knows maybe this will help me understand how it works.
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About Peter Yu I am a research and development professional with expertise in the areas of image processing, remote sensing and computer vision. I received BASc and MASc degrees in Systems Design Engineering at the University of Waterloo. My working experience covers industries ranging from district energy to medical imaging to cinematic visual effects. I like to dabble in 3D artwork, I enjoy cycling recreationally and I am interested in sustainable technology. More about me...

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