Bump Maps

Argent6978

I was wondering if someone could help me with a little thing I'd like to do. I went in to PhotoShop, pulled up the bump map image for Lilith 6 HD, and edited it to add some slightly raised places on my character's skin. It worked in testing when I rendered a simple character I pulled up using the DAZ 3Delight built-in render. Now I'm trying to get it to work with my Reality > LuxRender combo, and I haven't had much success. I'm not sure if there is another file I need to edit to get the bumpy places to appear on the skin through LuxRender, or what. Any help would be appreciated. I'm using the latest versions of all the software and plug-ins. Thanks!

SpottedKitty

This is easy to do, but there are a few gotchas. You've done most of it, there are just a few things to check.

When you edited the bump map, did you edit and save over the existing file, or copy it and edit the copy, immediately saving it with a distinct name? If you have saved over the original file, it's easily fixed by reinstalling Lilith.

The original bump map file is probably a jpg. Did you save the edited file as a jpg? Note that the jpg file format gets its huge file size compression by throwing away unnoticed detail; this happens every time you save as a jpg — the end result, if you do this too often, is a fuzzy image that will probably show when you render. If you re-save an image map, use a format like png or tif that doesn't do this. You can convert back to jpg, but be careful with the compression settings and make abolutely, definitely sure you're completely finished with editing the file. Jpg is a final format, not a working, still-being-fiddled-with format.

If you did save a copy of the bump map, the Lilith file you see in the content pane doesn't know about it; it would load the original bump map. You need to go into the Surfaces pane of Lilith, select the relevant skin surfaces (which part of the skin did you edit?) and change the Bump Strength map setting to your edited file. Now you can save the edited Lilith (UNDER A NEW NAME!!!) as a Character Preset.

I don't have Lilith; she might have a Normal and/or Displacement map as well as a Bump. This will complicate things.

I use Luxus, not Reality, so I'm not sure how well the bump settings are converted for LuxRender. The big difference is that the units for Bump Strength in 3Delight is centimetres, but in LuxRender it's meters. In Luxus I have to check every surface with bump to make sure it has a sane value. Apparently if LuxRender detects an "impossible" bump value it uses a default setting of a tiny fraction of a millimetre. This might be the cause of your lack of success, if everything else seems to be OK.

Argent6978

Thanks for the reply. :)

When I manipulate files, I always save them as a second copy, so I don't save over my originals. ;)

I did save the new bump map file as a JPG. I hadn't thought about using a higher quality format. I just thought I'd use the same format that the original file was in for simplicity's sake. I might have to look at trying that.

I did go into the Surfaces tab and apply the new bump map material to the bump strength map on the face and torso, as those were the only places I edited to be different.

I'm curious as to how a Normal map complicates things. She does indeed have one. Do I have to go into the normal map and do something to apply my shape there too? That's going to be a pain.... What I did in the Reality plug-in, I added my bump map images to the materials under the displacement map... I wasn't sure about that, but it's the only place where there is any reference to bump. But there was no choice to choose a bump map file, just Normal map and Displacement map...

Again, thanks for your help! :D