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Poser - OFFICIAL F.A.Q (Last Updated: 2024 Nov 29 7:57 am)



Subject: Bug in poser bump mapping and solution


gillan ( ) posted Tue, 06 November 2001 at 2:50 AM · edited Fri, 29 November 2024 at 4:09 PM

file_229737.jpg

In Poser 4 there is an error in the calculation of the bump. this is caused by a wrong compilation of the map of rugosity. I will try to explain, with my bad English, how resolve the problem I create a simple map of Bump, for instance bumptest.jpg, (illustration 1), after have it imported as bump map in poser (bumptest.bum), I apply it on a box. If I have a single light from the top the effect of depth and rugosity is perfect (illustration 2) But if I move the light to 45 degrees I get a paradoxical effect (illustration 3) this prevents from carrying out bump mapping efficent in Poser! the wrinkles on a face become cracks! I With Photoshop use the order "Open as" and I open the Bumptest.bum like if it is .bmp (illustration 4) now I in the "channels" select the red and I operate [image-adjust-invert] (illustration 5) Save as bumptest.bmp then I rename the file bumptest2.bum it loaded in poser and I apply it on the box instead of the the original one the effect of depth now is perfect. you try! finally could be used the maps of depth in poser!


vronsky ( ) posted Tue, 06 November 2001 at 5:51 AM

very thanks!!


neurocyber ( ) posted Tue, 06 November 2001 at 8:13 AM

Yup! Same thing happened to me.


Roy G ( ) posted Tue, 06 November 2001 at 12:21 PM

Will this technique work when the light is moved to other angles, or if camera settings are changed. It?s possible that Poser is making a compromise here and is going with something that works most but not all of the time.


Roy G ( ) posted Tue, 06 November 2001 at 12:27 PM

Something seems to be wrong with the paste function on this forum. Sorry about the odd punctuation above.


MartinC ( ) posted Tue, 06 November 2001 at 3:53 PM

file_229738.jpg

This is an interesting post, but I have a serious problem with it - I can't really confirm it. Above you see four pictures, left to right. From left to right, number 2 is the Poser4 bumpmap conversion of number 1, and number 4 from number 3. If you look closely, then number 1 (the black circle on white background) is *not* converted as reported above, while number 4 is actually the "repaired" version. It looks like that (at least) my version of Poser converts them very different to gillan's copy, and - to my knowledge - the appearance of my samples is indeed the correct conversion. Could this be a PC-only problem that doesn't show on Mac?


Ghostofmacbeth ( ) posted Tue, 06 November 2001 at 8:38 PM

I was wondering the same thing because black is always negative for me and white is the top of the bump. I am on a Mac too



troezi ( ) posted Wed, 07 November 2001 at 3:09 AM

No, I think you shall invert the red channel only not the whole pic.


MartinC ( ) posted Wed, 07 November 2001 at 4:14 AM

Sorry, this is a misunderstanding. I did not try to change/edit/repair anything, I just showed that there is no need to repair anything for my own copy of Poser. gillan seems to get his #4 out of his #1, and his #4 indeed is invalid. There is no wonder that he experiences problems with it, because it is some sort of "M.C.Escher" paradox - there is no grayscale template in existance that could/should create his #4. However, my copy of Poser takes the same #1 and creates my #2 - which is perfectly valid, and obviously very different to gillan's #4. If gillan takes his #4 and inverts the red channel, he ends up with his #5, which is a valid bumpmap - however it is not the valid one that should be made out of #1 - it is the valid bumpmap that normally gets created out of my #3. So the facts are: - my (Mac) Poser creates valid bumpmaps - gillan's (PC) Poser creates a damaged conversion, for whatever reason The questions are: - is every PC Poser converting the wrong way - are there Mac Poser's who also create damaged conversions. Could people check it? Please create a black circle on white background (like both our #1's) and let Poser convert it. Does the result look like my #2, or like gillan's #4?


MartinC ( ) posted Wed, 07 November 2001 at 4:24 AM

file_229739.jpg

I suppose all this #1, #2, #3 is terribly confusing... Look at the this template. Please create a black circle like this, and let Poser convert it. Does the result look like the "right" or like the "wrong" result. Or even different...? :-)


EnglishBob ( ) posted Wed, 07 November 2001 at 9:33 AM

For interest more than anything - my Poser 3.01 / Windows 2000 gives the wrong result also. Looks like this has been in there for a while. I never noticed it because I hadn't tried to do anything so geometric with bump mapping, but it would explain why BM doesn't always seem to give the expected results...


gillan ( ) posted Wed, 07 November 2001 at 9:47 AM

You excuse me Martin but I think that he is simpler set the question in this way: Your bump map in poser works correctly or to the "Escher-way" mistake the highlight? (you too see the others my two tests at Subject: Re: Bump bug resolution www.renderosity.com/messages.ez?Form.ShowMessage=453188 The differences of the conversion between mac and pc and of the direction of the light are creating confusion! However, to answer Roy, when poser mistake, it always mistake any it is the direction of the light (except the vertical one simple) and of the camera.


troezi ( ) posted Wed, 07 November 2001 at 10:29 AM

When I compare gillans correct version (#5) and MartinC correct version it seems as if gillans still needs to be rotatet 180 deg. Right?


troezi ( ) posted Wed, 07 November 2001 at 10:30 AM

Oops there should be "MartinCs correct version" - Sorry


MartinC ( ) posted Wed, 07 November 2001 at 12:38 PM

gillan, my (Mac) version above works as it should in Poser with all angles of light - that's why I just named it "right". I think it also is the correct up/down orientation - according to the manual, black means "down", white means "up". It looks the other way round in the olive .bum file, but if you apply it to a Poser object, the lights are correct. Your "red inversion" indeed repairs the .bum file to a valid ("non Escher") map, but I if I'm right it is inverted (look at my first sample in post 6). So I think the correct way to fix it is probably to invert the green channel. Is this bug really in every PC Poser? I can hardly believe this...


_dodger ( ) posted Wed, 18 December 2002 at 12:41 PM

I'm a bit bewildered by this, in that in a bumpmap, white should be high, not low, and thus the 'perfectly fine' lit from above version is completely wrong to me... the highlight on the indented circle should be on the bottom edge of the circle, not the top.


EnglishBob ( ) posted Wed, 18 December 2002 at 12:50 PM

Attached Link: http://www.angelfire.com/art2/cheapskate/bumpmaps.html

This thread has become a bit confused, but the wrongness applies whether dealing with "sticky-out" (white) bits, or "knocked in" (black) bits. For an alternative viewpoint follow the link to the simplified version on my site.


_dodger ( ) posted Wed, 18 December 2002 at 1:28 PM

Gotcha. I'm still trying to work out a combination of Photoshop filters that will correctly create a bumpmap BUM type from a bumpmap greyscale type manually. I've also noticed that you can get nice nice enhancement effect by running an unsharp mask filter on the bumpmap. And finally, last but not least, I should sit down and build a BUM corrector CGI script and put it up on my Free Stuff page. I can, pretty easily, make a CGI (uhm, perl common gateway interface, not computer generated imagery) script to upload a BUM, invert the green channel, and hand the file right back.


EnglishBob ( ) posted Wed, 18 December 2002 at 6:06 PM

Now that would be useful. The opportunities for cheap humour would be unrivalled as well; although I understand that the word bum is funnier in Britain than in the US. :-)


_dodger ( ) posted Wed, 18 December 2002 at 7:31 PM

Anyone who's been following this thread and hasn't seen my related threads in Poser Technical should probably look at This and this. Thanks EnglishBob for directing me to this thread. BTW, EB, It's funny in Aussie, too, and lots of Americans know the term -- at least when you complain about how big the bloody BUM is or how if you load a JPEG compressed BUM as a BUM in PPP and P5 it gives you a double BUM, which is always bad. B^) OT: I recall something I saw a tape of from BBC news ages ago -- during the news there was a cooking bit, and someone named 'Fannie' was sharing her biscuit (cookie) recipe. When it switched back to the anchorman, he looked dead at the camera and without a thought, said 'That's wonderful, and let's hope that all your biscuits turn out just like Fannie's'.' You could see the screen go blue as the camera adjusted for the sudden increase in redness in the anchorman's face when he realised what he'd just said. And VERY few Murkins will get that! (Nor will they find any irony in their cheerleaders 'rooting for their team'.)


MartinC ( ) posted Fri, 20 December 2002 at 2:43 AM

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

While it's always good to have a variety of tools and alternatives (like the suggested cgi script), you can already find tools to fix this problem: 1) On PC search FreeStuff/Utilities for "Green thingie" - this tool will fix the problem technically better than the "PhotoShop invert" method. 2) On Mac search FreeStuff/Utilities for "SpeedBump", or go directly to my website (follow this link).


EnglishBob ( ) posted Fri, 20 December 2002 at 3:08 AM

Thanks for the info, Martin. Green Thingie slipped my attention somehow. Must update my tutorial. Christmas holiday? What holiday? ;-)


illusions ( ) posted Fri, 20 December 2002 at 9:45 AM

Attached Link: http://www.renderosity.com/messages.ez?Form.ShowMessage=224045

I discovered the trick of making bum maps for Poser 4 using Photoshop about 2 years ago. Click the link to read the original discussion and see the examples. It's interesting to note that I was using a P100 Win95 PC and black DID indent.


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