I do not know what reference you are making, I am a bit clueless with UE4 maps. I would like it to appear as nice as I make it in Toolbag, or roughly about.
If you're making something that's entirely not made of metal, just leave metalness alone. If it's entirely made of metal, just put a constant 1 into it. If the object is partially made of metal and partially not made of metal, you'll need to put in a texture to mask out the different areas depending on whether they're made of metal or not.
Use the roughness texture to emulate the behavior that you would have used a specular color and specular power map for in UDK. To get a feel for how it works, I recommend making a material with a floating-point parameter exposed and wired up to roughness. Then you can mess with a roughness slider on a material instance and see the changes in real time.
I do not know what reference you are making, I am a bit clueless with UE4 maps. I would like it to appear as nice as I make it in Toolbag, or roughly about.
You can not use a specular map like you can in Marmoset Toolbag. The specular input in UE4 isn't what it seems, what it actually does is act as a multiplier for non-metals, its basically a cavity map.
How the metalness map works is, for metals (white in metalness map) the specular intensity/color (reflectivity) is pulled from the albedo map. For non metals (black in metalness map) the reflectivity is set to a fixed value of 0.04. With the metalness map workflow in UE4, you can't set the specular intensity/color directly for non-metals.
If you want to preview your textures in TB2 before sending off to UE4, use the UE4 preset material in TB2 (in the presets dropdown in the material editor). This will give you a normal map, albedo map, roughness map, and metalness map input.
The roughness map is also different from the gloss map in TB2, the values are mapped in the opposite direction. With a gloss map, black = rough and white = glossy, while a roughness map (at least in UE4) black = glossy and white = rough. The UE4 preset material in TB2 takes this into account and turns on the invert option so you can load your roughness map.
its also important to understand what actually is a metal. If you have an object made of metal, but coated with some other material like paint or rubberized finish, that wouldn't be metal. Only raw metals should be tagged as metal. Partial metalic values (gray values other than 0 or 1) generally shouldn't be used either (except for transition areas to show a soft edge between dirty or rusty effects).
For PBR, use whichever input your target engine specifies. For example Toolbag allows you to choose metalness or reflectivity, cryengine favours reflectivity, UE4 favours metalness. They are all physically based renderers.
Right, PBR does not necessarily mean using a metalness input. More than anything the metalness workflow is a way to optimize the content and is not mutually exclusive to PBR. A full color specular input can be used, and is actually more precise.
Though this isn't something individual artist will have a say in, you'll generally use one or the other for your project.
For PBR, use whichever input your target engine specifies. For example Toolbag allows you to choose metalness or reflectivity, cryengine favours reflectivity, UE4 favours metalness. They are all physically based renderers.
For UE4, use metalness.
Thanks for clarifying as I worded that poorly. I meant it as Using PBR IN UE4.
Replies
For PBR and UE4, yes use metallness.
Use the roughness texture to emulate the behavior that you would have used a specular color and specular power map for in UDK. To get a feel for how it works, I recommend making a material with a floating-point parameter exposed and wired up to roughness. Then you can mess with a roughness slider on a material instance and see the changes in real time.
You can not use a specular map like you can in Marmoset Toolbag. The specular input in UE4 isn't what it seems, what it actually does is act as a multiplier for non-metals, its basically a cavity map.
How the metalness map works is, for metals (white in metalness map) the specular intensity/color (reflectivity) is pulled from the albedo map. For non metals (black in metalness map) the reflectivity is set to a fixed value of 0.04. With the metalness map workflow in UE4, you can't set the specular intensity/color directly for non-metals.
Read more about this here: http://www.marmoset.co/toolbag/learn/pbr-practice
If you want to preview your textures in TB2 before sending off to UE4, use the UE4 preset material in TB2 (in the presets dropdown in the material editor). This will give you a normal map, albedo map, roughness map, and metalness map input.
The roughness map is also different from the gloss map in TB2, the values are mapped in the opposite direction. With a gloss map, black = rough and white = glossy, while a roughness map (at least in UE4) black = glossy and white = rough. The UE4 preset material in TB2 takes this into account and turns on the invert option so you can load your roughness map.
its also important to understand what actually is a metal. If you have an object made of metal, but coated with some other material like paint or rubberized finish, that wouldn't be metal. Only raw metals should be tagged as metal. Partial metalic values (gray values other than 0 or 1) generally shouldn't be used either (except for transition areas to show a soft edge between dirty or rusty effects).
To clarify here:
For PBR, use whichever input your target engine specifies. For example Toolbag allows you to choose metalness or reflectivity, cryengine favours reflectivity, UE4 favours metalness. They are all physically based renderers.
For UE4, use metalness.
Though this isn't something individual artist will have a say in, you'll generally use one or the other for your project.
Thanks for clarifying as I worded that poorly. I meant it as Using PBR IN UE4.