Hi folks. Lunedust, I got your PM. Sorry I took so long to answer - I have a lot going on at the moment.

So I've put together a little demonstration for freckles. I'll be posting a number of images. No questions, please, until I say I'm done. I have quite a bit of writing to do.

Under "3D Textures" we have quite a few nodes that create interesting patterns, based on various mathematical models of noise. The one that interests us for this problem is the Spots node.

I find it best to learn how these nodes work by attaching them to a one-sided square, or a sphere, and messing with the parameters and doing test renders. Try that now yourself. Load a one-sided square, open the material, and add a Spots node, connected to the Diffuse_Color.

The spots node has two color parameters - the Base_Color and the Spot_Color. Change those to different colors and examine the results. Basically the math creates an interesting-shaped gradient, which is then used to blend between the two colors.

While it is possible to do freckles directly in the Spots node, I prefer to work with a separate Blender node, driven by the Spots. You'll see why later. So you want Base_Color = BLACK (RGB 0,0,0) and Spot_Color = WHITE (RGB 255, 255, 255).

The next parameter is the Spot_Size. This is the overall scale of the pattern, and is quite predictably. Vary the Spot_Size and do test renders. Try setting it really small. When the value gets small enough, the spots devolve to speckles and look like pure noise. Also, the preview in the node pretty much disappears. Don't worry, the spots are still there. Do renders to see the final outcome.

Go back to a bigger Spot_Size, now, so you can easily see the details changed by the remaining parameters.

The Softness causes the spots to have fuzzy edges. The Threshold adjusts the balance between how much is mapped to Base_Color versus Spot_Color. In practice, when you change one, you generally have to change the other to keep the ratio in the same balance. This is unfortunate, but we have to live with it.

The next parameter is the Global_Coordinates parameter. What this does is very simple. The underlying math is evolving the pattern based on the local coordinates of the geometry. In other words, regardless of how you scale or rotate the geometry, the pattern will cover the geometry in the same way. If you enable Global_Coordinates, then Poser will use coordinates from the geometry after it has been scaled, rotated, and translated. We don't want to use this here, so leave it off.

The last parameter is Noise_Type - Original or Improved. Somewhere along the development of Poser, they added improved "noise" functions. The original suffers from some drawbacks resulting in visible repeating patterns. We usually don't want the original method except for backward compatibility with old shaders, so you should generally set this to Improved. However, experiment as you like, and sometimes you might just like the original patterns better.

Because the Softness and Threshold parameters are tricky, I'll give you a chart that you can use to visualize what they do and help pick a starting point for your work.

 

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