How to add a simple overlay on top of an existing texture in Poser:
The overlay has not destroyed the original glossy effect, I just took that off manually to make for a simpler demonstration of the nodes.
1. At the top Diffuse node, right-click and disconnect the connector to your current 2D texture. This does not destroy the texture. It’s still there waiting to be re-connected.
2. Right-click the empty Diffuse slot and there plug in a new Math | Color Math node.
3. Set the Color Math node’s Argument to Multiply. Also have both of its values be pure White.
4. Connect the Color Math node’s Value 1 slot to the original texture map.
5. On the Color Math node’s Value 2 slot, right-click and then add a new standard 2D node.
6. On the new 2D node you then load your overlay as a square 2D image source, in the usual way. Pure b&w appears to work best.
Here we have a puny low-res dash-shading overlay for demo purposes. Nor is it even uniform, which it ideally should be…
For dash or hatched-shading of the object you may want to dial this source’s U and V scales down from their 1.0 settings, to something like 0.10 or 0.12, as seen here.
You can save this as a standard material setup, and then just switch the source texture and overlay texture. Obviously you’d use a seamless tiling texture, which I haven’t here.
Of course, it would be nice to have the overlay effect render on its own. There are two ways to do this, that I know of…
1. Also plug the overlay into the Alternate Diffuse, which should be set to white. You then see the change in the Preview. Then render again, in Preview even. In Photoshop, knock white out of the render with an automated Action.
2. Also plug the overlay into the Custom_output_1. There will be no change in the viewport.
But if you render to Firefly with the following settings…
… and save as a Photoshop .PSD then you get a nice Photoshop layer of the effect on its own…
Yes, ugly seams… but this is just a quick demo. The seams could be fixed.
We still don’t have it in a form where the white is transparent, but any good Photoshop Knock Out White Action will do that.
Of course, it may be possible to just leave the whole current material setup alone, and just plug your overlay shading into the Custom_output_1. I’ve yet to investigate that. Though that would limit you to Firefly rendering only. But doing it that way should be simple and reliable enough for a script to handle automatically.