I know there's a process to doing this. Does everyone do it the same or are there several different ways. Does poser pro make bump maps from colored images or do they have to be processed first. I know these questions have been answered before but I can't seem to find the threads so can someone help me out here please? I either need to know the process or if it's automatic with the pro pack. However I'd still like to know the process. I thought it was something like convert the image to greyscale then invert it.....or something like that...help? Thanks in advance.

This won't be the ideal answer but its a Poser amateur's version of one anyway ;) You can use the texture map as a bump map as is (this is probably just a pro pack thing). However, its usually (always?) better to make it a grey scale. Inverting it sometimes gives you what you want sometimes it doesn't. Usually you have to still tweak it. The bump map works by the lighter the shade the more "bump" there is. I try to think of mid grey as flat and then darker areas are recessed and lighter areas raised (I may be slightly flawed in this but it seems to work for what I want). Think about a typical texture. A 3D look is given by highlighting raised areas and shadowing recessed areas. If you invertthat then you'll get them the wrong way for your bump map. Or that's the way I see it and can't understand why some people say to invert the greyscale. Please, someone explain how that works if I'm wrong :)

You can use colour templates, but they may create unexpected results, since Poser will use the "value" instead of "luminance" - this means that primary colours like 100% red are actually the same as 100% white (which is not what you probably intend... :-) With greyscale templates "black" will be a "mountain" while "white" is a "hole" - but this can be easily inverted in Poser when you load the map.

• a P4 question? - also read P. 247- 251 of the P4 manual.(Chapt 11 - Surface Materials.) Although the manual was far from complete in this case it will at least, in combination with steve-law;s post, get you started.

Yes, and in the manual it says "The darker you paint, the more depression you create on the surface of the object. Use 50% gray for medium depressions and solid black for deep indentations." Like I said and not how MartinC described it (unless he works at -100% by default ;)

Well actually no, not quite like I said it. White would be flat from that description, with the darker you get the deeper the depression. Does it really work like that?

Ooops - I guess I should read the manual occasionally... WELL,... there is a reason why I switched it, and it is known as the "great bumpmap desaster". As a matter of fact, the PC Poser creates damaged .bum files which won't work at all (the bug seems to affect most - if not all - PC versions since Poser3 days). Please follow these links for a detailled description: http://www.angelfire.com/art2/cheapskate/bumpmaps.html http://www.poserforum.net/ubb/ultimatebb.php?ubb=get_topic;f=5;t=004613 http://www.renderosity.com/messages.ez?Form.ShowMessage=454108 As a matter of fact, this bug does not affect the Mac version, but the .bum files created are definitely 1) black = mountain 2) white = hole You could see it either as a bug in the manual description, or a different bug in the Mac Poser. If you "repair" .bum files the way how it is described in the original thread you will end up with identical (and working) files on Mac/PC, so I guess it is better to regard the manual as buggy (especially because no one seems to read it anyway... :-)

Gah!? I'm going to have to read those a couple of times (especially the last one) before they make more sense. :) Martin, thanks for that it finally explains why you invert (I think ;) (But [how] does this bug thing effect pro pack and do you just invert the red channel?)

Erm, green or red then?

"As a matter of fact, this bug does not affect the Mac version, but the .bum files created are *definitely* 1) black = mountain 2) white = hole" ...hmm... I'm using PC Poser 4.03 (and a .bum file converted from a greyscale image) and the above are the results I get - you decide ;).

...to me, it looks like White = mountain an black = valley, as you'd expect. I might note though, that a lot of tutorials, etc. that talk about making bumpmaps start out with something like... "start by converting your image to grey-scale, then inverting it" ...what they are 'trying' to address (in a lame way) is the fact that many human texture features that 'stand out' are actually darker than the skin (nipples, moles, viens, beard and other hairs, etc). The problem is, doing it this way neglects the other features of the skin that don't work this way (wrinkles, etc). I think this is where a lot of this confusion comes from (?). - Keith

BTW, after investigating it more closely, I agree that there IS a bug in the .bum files as far as being correct from all angles... and I agree with Martin that the green channel is the proper one to flip. BUT, I disagree about the relative heights of black vs white... as you can see from the image above, white = higher and black = lower (even though the apparent agle of light may be wrong at some angles).

Hmm, curiouser and curiouser... Looks like you opened an old can of worms KiDAcE ;) Yes Spanki I'd definately aggree that in two out of the three faces (right and top) the white looks positive while the black looks negative. As for the difference in heights, yes I agree there too, but that would be caused if the grey is darker than 50% (I can't tell from the picture, what's the values?) I will try this myself when I get home (using pro pack). It would seem this has never been thoroughly tested has it (different platforms, setups etc.)? Its probably not going to grab people's interest now with Poser 5 seeming to take all the focus around here now.

Hmm, now I look at it again, the right hand face black shape looks to be indented, while the black writing looks raised (and all the white looks raised). Weird..

Ooops, Ooops, Ooops,... You are right, I was wrong. I hereby deny my black/white notes and start to claim the opposite... :-) I don't know why I confused it, but I was pretty sure when I wrote it, and my own testing files for SpeedBump cleary show that "black" indeed is a "hole". I guess I mixed it up since the "olive" binary conversion looks just like the opposite of the actual effect. So, it now is 100%, 24 carat: 1) BLACK = HOLE 2) WHITE = MOUNTAIN Apologies for any frustration... :-) And it definitely is the green channel which gets inverted, and the result is that shadows are only correct at 0 and 180 degrees, and worse at 90 and 270 degrees. I can't say anything about ProPack, except that the shadows seem to work on Mac. However, I never bothered to install the PC version of PPP, so I can't test it. I only have PPP for testing purposes and refuse to work with it, due to the outstanding number of bugs which make it virtually unusable on Mac.

If you are doing tests on PC then make sure to fix the green channel, otherwise the results are void anyway. The "damaged" .bum files work like an M.C.Escher picture - if the light rotates clockwise, the shadows will rotate counterclockwise, and therefore you can't use them to judge for mountain/hole surfaces.

So for all intents and purposes: Black = Holes White = Mountains To get the bumpmap I greyscale the texture and then to get correct shadowing I would then invert the green channel? Well sounds good. Sorry for the confusion with this I was a bit lost. Keep thinking blackholes and white mountains....wonder if it's the same in Poser5...the glitchiness/quirkiness. Thanks all for the feedback

Attached Link: http://www.soft-rabbit.com

That's right. Just keep in mind that the greyscale you create out of the (colour) texture doesn't automatically make sense (spots with strong colours are not automatically spots where there should be a "hole"). If you are on PC with Poser4 then load the bumpmap once, convert it to .bum, then open the .bum file in an ImageEditor (you may need to rename it to .bmp), invert the green channel, save it into .bmp and finally rename it back to .bum. On Mac you don't need to worry since Poser will convert it correctly. However, if you get a PC .bum file from the net that doesn't work, then you should best get my SpeedBump package for GraphicConverter since it makes the repair much easier (and more precise, btw.) than the "manual" method.

In the interests of science, here's mine. This a bump directly from the grey scale image, so there is no way to correct it for us pro pack users! So Curious Labs have never comments on this then? (I don't suppose they will be patching it before they stop supporting Poser 4 all together will they...)

Martin, coding question: to correct the green channel do you convert an unsigned character to a signed one, or simply invert the value, ie 0=255, 1=254, ... 254=1,255=0. - TJ

Martin,

Followup:
I made a small "C" exe for the PC to correct the green channel. Right now it's just in dos and only works on small
bmps (< 64K.)

what I started out with is on the left.
what I ended up with after simply taking the G value and
making each green value it's inverse(G = 255 - G). it looks like it works ok according to the thread. The upper image is your
image from gillans thread for comparison(so it's all on the same page. (if you have any objection to the image being there let me know and I'll delete it and repost an image sans your image.)

What do you think?

• TJ

TJ, You can't actually repair the problem completely since the template to .bum conversion adds rounding errors and loss of information that is not reversible. In other words, there is no way to exactly re-create the (bitwise identical) Mac .bum conversion out of the PC one (unless you still have the original template and convert from scratch). However, you can come pretty close by using this formula: if (G <= 254) G = 254 - G; else G = 0; So it's not really the bitwise invert (G ^= 0xFF or G = 255-G) but "one level lower". The "else" branch should not be necessary since the value can never be 255, however (with all those .bum hackers around) it's better to have it in. The Photoshop "invert" will end up with a value that is 0 to 2 levels wrong, while this formula above ends up with an average error of -1 to 1 levels, and is therefore much better.

Martin, Thank you for the discussion. It really helped my understanding of the problem. I'll modify the code to 254 rather than 255 and add the else statement. As I noticed that your converter was only for the MAC, would you mind if I posted one in freestuff for the PC? Right now, I've only got it working in DOS, but I would convert it to Windows, test it before posting, and would have to drum up a spobsor as I only have a free website on an angelfire that limits the amount of downloads. - TJ

oops sponsor not spobsor.