Specularity Not Working as it Should

This is a repost from what I have just posted over on the bd forums -

In the course of making a number of placeables I accidentally discovered that what it says in the NwN EE Wiki, specifically in the Standard material inputs article, is wrong. For months now, I have religiously made sure that my spec maps are 8 bit greyscale. I have also struggled to get any sort of reflectivity from the placeables that I worked on. Then, just tonight, I made a serendipitous (means happy accident) discovery. In my attempts with spec maps I have used the gimp to brighten these maps (its the only image editing software I have access to that will save 8 bit greyscale TGA files). In order to make them even paler, I tried loading some spec maps into paint.net. After that I saved them and tried them, forgetting that paint.net can only save in either RGB or RGBA. Upon testing I found the glossiness of the selected placeables was spectacular. Afterwards, I realised that the spec maps were in the “wrong” (24 bit, RGB) format and used the gimp to convert them into the “right” (8 bit, greyscale) format. Upon re-testing, I found that the glossiness had vanished again. Reverting them to 24 bit RGB restored it.

Conclusion - Either spec maps are supposed to be 24 bit RGB (not 8 bit greyscale) or there is a bug.


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Great info I myself was unaware of completely. I been just using TGA in 32bit thinking it was the best option on export and notice odd bugs like part of models specularity was were it should be, then some polygonal sides it seemed the UV map was not proper or the model did not have saved info within it to know how to utilize the space specular map properly. I Use 3DS Max and tend to fill each map slot under the main diffuse material (normal, displacement, specular level, etc.) Before I export with the same UV layout as the main diffuse UV so that when my MTR references the new PBR maps, they display properly. Somehow though even though I did this for spec maps, they tend to look funky or not aligned properly, or just not as specular as I like. I tend to use ShaderMap to create specular maps, and prior used CrazyBump. I’m not aware if you can even bake spec maps in 3DS Max or not. :smile: