Normal Maps: one more time please ...

marble

I know this subject has been discussed a number of times but I would like to get a feel for what people here think about normal maps vs bump vs displacement. I mean by preference rather than the technical explanation of how each work (as I said, there are a number of threads on that). One consideration is that Normal Maps can be used when the Displacement and Bump slots are already occupied - I notice a lot of vendors do that.

The second part of the question is how to make normal maps. I know that some use online converters, some use Photoshop (I think - I don't have PS so I don't know that for sure), some use something like Materialize and others use ZBrush (again I don't have that - I don't have a budget for expensive software).

Part #3: do you "paint" your normal map image (i.e. make a greyscale image and convert it to a Normal Map) or create one from a sculpt in either ZBrush or Blender?

By the way, this question arose (again) as I was reading another thread which asked how to add creases and wrinkles to cloth. One answer was to add them with a normal map but I am never really sure how to do that. I think it might involve UV Mapping which is another dark art that I am clueless about.

Richard Haseltine

Well, one way to make normal maps is to sculpt the details you want on a high resolution of the model, then bake that to a standard resolution model (that's how ZBrush is sued, but Blender can do it too). Another option, which some of the other tools you mention do, is to process a 2D image and "extract" the relief data from that (scare-quotes as I can't say I've been impressed with the results) to make a bump/displacement or normal map. Another way is to take photos with multiple light sources in sequence and analyse the data to get a much better idea of height and other properties (photogrametry)

lilweep

marble said:

Part #3: do you "paint" your normal map image (i.e. make a greyscale image and convert it to a Normal Map) or create one from a sculpt in either ZBrush or Blender?

 

I guess you could just 'stamp' a specific normal map brush onto a 2D image, but painting them would seem a somewhat crude way of doing it.  There's nothing to stop anyone from doing this though.

I think most people are just baking them down onto a low res mesh from a high res meshes in e.g. Zbrush, Substance Painter, Topogun, Blender.  Same way they bake displacement maps.

 

marble

Richard Haseltine said:

Well, one way to make normal maps is to sculpt the details you want on a high resolution of the model, then bake that to a standard resolution model (that's how ZBrush is sued, but Blender can do it too). Another option, which some of the other tools you mention do, is to process a 2D image and "extract" the relief data from that (scare-quotes as I can't say I've been impressed with the results) to make a bump/displacement or normal map. Another way is to take photos with multiple light sources in sequence and analyse the data to get a much better idea of height and other properties (photogrametry)

OK so a high-res sculpt looks like the best method without getting really serious with taking photographs (with a real-life model, I presume). I've seen discussions of baking the HD details on G8 to normal maps but have no idea how it is done in Blender. I'm guessing there will be tutorials for that though. I did try painting a greyscale image and using Materialize to make a displacement map from it but, like you, I was not impressed although my skills at painting such detail left a lot to be desired.