I need to separate the question "Do you need it when ..." into two.

VSS (the script) and VSS Template Skin (the shader) are really two separate things bundled together. You can use VSS (the script) with your own templates or with other templates by me such as the Vargas shader and its purpose and value is in making it convenient to apply a common shader to many material zones in one step. So the question of needing VSS with IDL implies that VSS has something to do with rendering and it doesn't. VSS is a way of editing materials without doing all the zones by hand.

So now I think your question really is do you need a complicated skin shader, such as the one I published in VSSPR3, when using IDL and the EnvSphere?

The answer is complicated, but for the most part, yes. Could you use a simpler shader? Yes. Could you get good results with a simple P4-style shader? Yes to that as well. But it won't be as good with so many of the shader elements missing.

The shader I supply has a number of features. Some are completely still needed, some can be applied at a lower strength, and some can be eliminated altogether with no loss of quality.

Let's take the shader elements one-by-one:

Skin-tuned specularity with conservation of energy: You need it - without this the skin will not quite look so much like skin, but rather more like bad computer graphics doing plastic or rubber. The built-in Specular effect is not right for skin - must use Blinn and must configure it correctly.

Shader GC: No question you need it unless you have Poser Pro 2010 with render GC enabled. In that case you not only don't need shader GC, you must not use it. You would set the shader gamma to 1.0 in that case. When using it without render GC, and without IDL, you want it just as I shipped it, set to 2.2. When using it with IDL but not render GC, you want to tone it down to around 1.3.

Fake SSS: With IDL this is almost unnecessary and can be left out or turned off with great success. However, a small amount still enhances the look of translucence, making the skin look more real. When IDL is on I reduce the strength to below .5.

Boost: This is a final luminance amplifier and not at all necessary, but incredibly convenient for fine-tuning the overall brightness of the skin versus other things in the scene that, perhaps, are a little bit in disagreement about what the "nominal" correct "exposure" (light level) is. If everybody would agree to use my light meter before publishing their shaders, then everything would be calibrated to the same amount of "correct" lighting and you wouldn't need the boost option. You use it to raise or lower the skin luminance relative to everything else. For maximum utility I really should have divided this into pre-amp and post-amp, but it's pretty useful as is.

Shader AO: Not needed at all with IDL and will automatically be shut off when IDL is enabled.

So I would summarize the answer as; you can get away with a simple skin shader, but you can do better with VSS PR3 Template Skin, provided you adjust parameters a little. Note: The precise adjustments for P8 IDL use are found in my free "Soft Studio Lighting" tutorial scene. It's in my free stuff.

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The only thing VSS affects on your figure is it changes the shaders in the materials. Once changed, you can save the materials and recall them without having VSS involved.

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VSS is needed for any scene in which you're tired of manually editing shaders.

My shaders that come with VSS are needed at all times in all scenes for that last 5% of realism, getting you within 95% of the best that is possible in Poser. But you can get 80% without it in P8, and 90% with PPro 2010.  That last 5% is all about you and not the tools. grin

 

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Renderosity forum reply notifications are wonky. If I read a follow-up in a thread, but I don't myself reply, then notifications no longer happen AT ALL on that thread. So if I seem to be ignoring a question, that's why. (Updated September 23, 2019)