Someone pointed me to an easy way to use texture maps as bump maps, but how about specular maps? Or is there a relatively easy way to make a spec map? Thanks!

The trouble with specularity maps is that they are more attuned to the material of your object that you are representing than they are to the diffuse map representation of the object. You can use a graphics editor to tweak a diffuse texture map to represent your required specularity settings, but it takes time and practice to accomplish this in a realistic fashion and isn't always easy with maps with multiple types of spec.

Converting Diffuse texture maps to specularity maps is always going to be a bit more hands on, this can be made a bit easier with specific software such as Quixel which has a Texture map baker that allows you to tweak on the fly in real time on your actual model selecting various base materials which will be represented in your specularity map.

An example of where conversion of diffuse maps becomes an issue is something like a Snooker 8 Ball. The texture map has two sections, the majority black of the ball and the smaller white area with the number 8 in it.

The issue is that the specularity map for the ball needs to be just plain white as the entire ball has an even specularity over its entire surface, which represents the material the ball is made from not the diffuse appearance. Converting the diffuse texture map will give you a black section with 0 specularity and a white section with %100 specularity and no amount of tweaking will give you the results you require(Except for filling the entire section white). In this case and many others the diffuse is totally irrelevant to the specularity of the object so it can be hard to build from.

Here is a promo video using Quixel to give an idea of how this kind of thing can help in your workflow.

@DocMatter wrote: "Someone pointed me to an easy way to use texture maps as bump maps, but how about specular maps? Or is there a relatively easy way to make a spec map? Thanks!."

If that "easy way" with bump maps was to run the texture map through a Math Functions node to turn it grayscale and adjust the brightness/contrast, you can do the same thing to make a procedural specular map.

As far as I understand it, you don't really need a specular map, per se, unless you want to control which parts of the diffuse texture get more or less specular light. Spec maps (greyscale images) usually get plugged into the Specular Value input on the PoserSurface root node, not into the Specular Color input, so they provide control over the intensity of the specular highlights -- from 0 (black areas of the spec map) to 1 (white areas) -- but they don't contribute to the color of the highlights or their type (glossy, blinn, etc.).

If you don't need to have the specular intensity correspond closely to the texture map, then you can just use one of the nodes under Lighting to provide the type of highlights you're after -- like Blinn for skin or other soft surfaces, or Glossy for hard, shiny or wet surfaces. You don't need to to plug a spec map into those nodes, although it's possible to do so.

If you've used EZSkin on a figure's skin materials, you'll see that it ends up connecting a procedural bump map to the Reflectivity input on a Blinn node (which is connected to Alt_Specular, with the regular Specular blacked out). In fact, a good way to learn more about options for procedural bump and spec maps is to delete any image-based bump and spec maps that came with a figure's skin materials and then run it through EZSkin. You can then study the nodes that go into creating the procedural bump and specular and experiment with them to learn more about how they work and why.

Of course, all of this assumes you're using Firefly and not Superfly. If you were asking about spec maps for Superfly, never mind! I use Poser Pro 11, but I don't use Firefly b/c my projects call for a style that Firefly is better at.

With a standard photo it will not be easy, the value of the pixel includes both diffuse and reflected light component. For non metals the spec colour matches the colour of the lighting so if that is known it may be possible to filter out the diffuse contribution. Another approach could be to use polarisation to remove scattered light when taking the photo. Also spec is very directional so unless even lighting was used to take the photograph you'll get a direction baked into the image that may clash with the scene lighting.

Depending on what you're using the spec for the faked bump map can be useful, for example a raised part of the map may be a different material or may be worn to have a smoother surface.

In most cases the shiny parts and the matte parts are going to be different pieces or different materials anyway, so you don't need a map to control the shininess. On a car, the chrome and glass will be shiny, tires will be matte, and body paint in between. Those will almost always be different materials, so you can just set the specularity for each.

On face makeup, the shiny parts will be the eyes and lips and possibly eye shadow. The eyes and lips will typically be separate materials. You might need a map for the eyeshadow. You can use the color to make a grayscale mask in Photoshop for specularity.