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View Full Version : Image bump mapping: kinda wimpy



jeric_synergy
07-30-2012, 12:47 PM
I recently used bump mapping with an image and the amount of apparent 'bumping' I got, even with 10,000% amplitude, seemed rather wimpy. The image's (attached) white is 255, so I'm puzzled why I can't get a good (illusory) offset.

Whereas a procedural texture such as Turbulence results in quite a bit more apparent bumpiness.

??

Thanks.

JoePoe
07-30-2012, 01:23 PM
Jeric - make sure you have a bit of a greyscale gradation from black to white (or grey to white). Otherwise make a normal map.

Danner
07-30-2012, 01:25 PM
What Joe said, a little blur will sell the effect much better. Also make sure you have "use bumps" in your radiosity settings.

lardbros
07-30-2012, 01:39 PM
If you're using Radiosity that is... otherwise it won't make any difference.

jeric_synergy
07-30-2012, 01:42 PM
Thanks all. :thumbsup:

(Normal maps remain a mystery to me: every tut various helpful & kind individuals have pointed my sorry *ss @ has seemed to involve a hundred steps and several downloads.)(Harumph. Get off my lawn!)

stiff paper
07-30-2012, 01:46 PM
Bump maps are kind of... slightly rubbish, really. And very, very old tech now, from back when 112 polygons with a single 128 by 128 color texture was a big render. They're great for a fairly limited range of things, and you just have to get a feel for when they'll look good and when they won't.

All you see with a bump map is the "transition" area, brightened from one direction and darkened from the opposite direction. If your map has a hard edge from light to dark or dark to light, there isn't a transition area, so you get very little effect.

The best results with bump maps come with maps that have a full spectrum of grey tones with plenty of nice ramping gradients. I've had excellent results from bump maps for rough hewn wood surfaces, although that has been mostly for more cartoony looks.

jeric_synergy
07-30-2012, 01:50 PM
That hard transition is probably the villain here.

Thanks!

XswampyX
07-30-2012, 02:03 PM
It's well worth the extra effort to get a normal map made.

http://i465.photobucket.com/albums/rr16/xXswampyXx/BmpVsNormal.gif

Here's one I made earlier. :beerchug:

stiff paper
07-30-2012, 02:21 PM
Yes, it really is well worth the effort to make a normal map. That way you'll get proper lighting on your faked details rather than a trick.

You can't tell radiosity to ignore normal maps though. I had a scene that used some big normal maps a while back, and I ended up having to replace them with bump maps because they sent the render times through the roof.

lardbros
07-30-2012, 02:25 PM
Just out of interest swampy, are you using the nvidia plugin in photoshop for those? I tend to create most of mine using either that or the crytif one with the CryEngine, and it works perfectly.

Now... if we could do parallax occlusion mapping in LW that would look even nicer :)

Think DPont had a way of doing POM (parallax occlusion mapping) but not sure if it had any gotchas or anything.

By the way, sorry to confuse you further jeric... basically:

Bumps are only good for small bumpy things

Normal maps are good for slightly larger bumpy things

Parallax Occlusion maps are good for even larger things, and even have shadows that cast and the lumpy bits even occlude bits behind them etc. (hence the name)

and then displacements are used for the bits where you need ultra detail and realism, and not worried about poly-count etc.

lardbros
07-30-2012, 02:26 PM
Here's a link to some images of POM

https://www.google.co.uk/search?q=parallax+occlusion+mapping&hl=en&prmd=imvns&tbm=isch&tbo=u&source=univ&sa=X&ei=0e0WUMueFoi3hAeHjoGIAw&sqi=2&ved=0CGUQsAQ&biw=1745&bih=868

Luuuurvely!

lardbros
07-30-2012, 02:32 PM
Oh, and here's Dpont's node info on one he created called Relief Mapping (which I assume is a similar effect).

http://dpont.pagesperso-orange.fr/plugins/nodes/Additionnal_Nodes_2.html

As it says in his docs, it only copes with hard shadowing, and may have some issues... but it's a nice effect.

Waves of light
07-30-2012, 02:38 PM
What do you use to make your normal maps XswampyX? I'm in the process of trying out NVIDIAs normal map filter for PS.

Damn, should really refresh before coming back and posting a response... 4 other posts now before mine. Duh.

lardbros
07-30-2012, 02:43 PM
Sorry... got a bit excited... 3 of those 4 are mine :) Lesson for all... I should learn how to use the edit function rather than do a new post. Sorry all! :(

XswampyX
07-30-2012, 02:48 PM
I've just started using ShaderMap2.... It's very good, and quick! You can pretty much automatically make any kind of map from any other type.

http://forums.newtek.com/attachment.php?attachmentid=105845&stc=1&d=1343681082

Waves of light
07-30-2012, 03:16 PM
Now looks a better interface than the nvidia plugin. I also don't seem to be able to get that level depth with the plugin. I'm basically wanting better looking arch viz textures, so using normal maps instead of bumps. Sorry, bit of a highjack going on here.

lardbros
07-30-2012, 03:19 PM
Ooh, thanks Swampy... I'll have a look at that.


Here's my test using Dpont's relief mapping node. It's very simple to use, but can be a bit crashy with VPR. Looks quite nice though, and works with GI too.


Here's the scene and an image to show what the result is like.

jeric_synergy
07-30-2012, 03:20 PM
Hah, well, now that I've had my arse kicked enough, here's my first normal map, using the Nvidia Photoshop plugin. :D (Meant to be funny, I hope.) I'm not sure why I'm not getting the standard all-blue background, but OTOH I didn't read the dox either. Baby-steps. :jester:

EDIT: fixed it.

Thanks for all your patience: I'll also have to, as always, look into swampy's ever-elegant solutions. :thumbsup:

XswampyX
07-30-2012, 03:31 PM
Looks good! :tongue:

lardbros
07-30-2012, 03:50 PM
One of the most incredibly elaborate setups I've seen for Normal maps was for trees in Crysis. The poor guy who spent the last 7 years doing just foliage and trees must be going insane :)

Basically, he'd modelled all the trees and textured them in full detail. Then chose certain branches and sub-branches he liked, and set them up as separate branches, so they could be used seamlessly on trees etc. He then set up all the planes on low-poly branches, which were cleverly re-using UV space for similar sized leaves etc.

The clever bit was his normal map baking. He didn't use a plugin or any baking tools, but instead set up lights at the right colour, and place them on each axis. Having a bright coloured light on the +X and a negative light on the -X... and the same for the other colours. His branches were mainly modelled so they were almost facing Y, so he set up a very long lens, and just rendered this from the camera.

Awesome setup, but must have taken A LOT of time to get right... look amazing though.

Waves of light
07-30-2012, 03:58 PM
@lardbros some people are just too clever.

lardbros
07-30-2012, 04:04 PM
@lardbros some people are just too clever.

Yes, they certainly are... but just shows that even the big guns like 3ds max (as they used) still aren't up to the task of baking normal maps well. (I've tried in the past and get horrid seams, where-as a tool like polybump, or xnormal do a grand job)


On the thread of really smart people... here's another image done using DPont's relief mapping plugin. Really impressed by the self shadowing effect, looks believable. Only thing you obviously lose is the bump on the silhouette... but still, I've not used this in anger, so nice to test now!

stiff paper
07-30-2012, 04:37 PM
...but instead set up lights at the right colour, and place them on each axis.

When normal maps first appeared in games there weren't any tools, so you had to do it like that.

You can do something very similar in the real world to make normal maps from real objects, using a camera (stable, on a tripod), a movable light source, and then multiple shots with different illumination. Fairly flat objects work best, like a frieze, or maybe a rough table top, otherwise shadows are a problem.

Edit:
http://zarria.net/nrmphoto/nrmphoto.html

dblincoe
07-30-2012, 06:04 PM
http://crazybump.com/ is a good tool to make normal maps, occ, spec, diff maps.

lardbros
07-31-2012, 01:09 AM
When normal maps first appeared in games there weren't any tools, so you had to do it like that.

You can do something very similar in the real world to make normal maps from real objects, using a camera (stable, on a tripod), a movable light source, and then multiple shots with different illumination. Fairly flat objects work best, like a frieze, or maybe a rough table top, otherwise shadows are a problem.

Edit:
http://zarria.net/nrmphoto/nrmphoto.html

Oh yes, of course... Used to bake my own textures the old way... But just never did normal maps this way. :) It was an impressive setup for sure!