Forum: Poser - OFFICIAL


Subject: material coming out black no matter what

diomede opened this issue on Aug 25, 2005 ยท 23 posts


diomede posted Thu, 25 August 2005 at 11:29 PM

Really basic problem using Poser 6 Material room. No matter what diffuse color I use, no matter what lights I use, the prop is always black. Tried many things but the attached image came from the following. I made a prop (the dress) in another program then imported it into Poser as an OBJ. I then used the poser grouping tool to spawn a new prop from this prop and exported it from poser as an obj. I then imported this new obj prop back into poser and used the gruping tool to assign a new material to the dress. I assigned the color white to the material diffuse color and to the preview mode. I've also tried image maps. I'm missing something really basic.

kuroyume0161 posted Thu, 25 August 2005 at 11:47 PM

UV mapping?

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pokeydots posted Fri, 26 August 2005 at 12:16 AM

Maybe reversed normals?

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NomiGraphics posted Fri, 26 August 2005 at 12:37 AM

It is most likely reversed normals. When you do the import, tell Poser to reverse the normals and see what happens. - Noel


kuroyume0161 posted Fri, 26 August 2005 at 12:40 AM

Yep, I'll agree with pokeydots and spiritual. That would explain the white areas in the render - backfacing polygons that are showing the white color.

C makes it easy to shoot yourself in the foot. C++ makes it harder, but when you do, you blow your whole leg off.

 -- Bjarne Stroustrup

Contact Me | Kuroyume's DevelopmentZone


sixus1 posted Fri, 26 August 2005 at 12:59 AM

We had this happen recently and never did figure out what caused it. Took the obj in and out of both Maya and Poser. The obj rendered fine in several other applications, just not Poser. Anyone figure out what it is, I'd be happy to hear it :) --Rebekah--


diomede posted Fri, 26 August 2005 at 6:06 AM

thanks everyone. i imported the obj again and checked 'flip normals'. that did the trick.


pokeydots posted Fri, 26 August 2005 at 6:11 AM

Glad it worked out ;o)

Poser 9 SR3  and 8 sr3
=================
Processor Type:  AMD Phenom II 830 Quad-Core
2.80GHz, 4000MHz System Bus, 2MB L2 Cache + 6MB Shared L3 Cache
Hard Drive Size:  1TB
Processor - Clock Speed:  2.8 GHz
Operating System:  Windows 7 Home Premium 64-bit 
Graphics Type:  ATI Radeon HD 4200
•ATI Radeon HD 4200 integrated graphics 
System Ram:  8GB 


an0malaus posted Fri, 26 August 2005 at 8:52 AM

Nice to see a quick fix there :-) @sixus1, the obj format can actually indirectly record vertex normals in two ways. One is the vn x y z lines which Poser doesn't need and the other is the face winding order which Poser uses to determine the vertex normal vectors using (I believe) the vector cross product of the two face edges adjacent to each vertex. The easiest way to remember which way the normal will face from the face vertex order is the "Right Hand Thumb Rule". With the fingers of your right hand curled round and your thumb extended, orient your fingers to point in the direction which follows the order the vertices are listed in the face f line. E.g. If they're listed clockwise, your thumb (and the normal vector) will point away from you. If they're anti-clockwise, the vector will be towards you. It is possible to confuse Poser (as I've done by hacking obj files by hand) if the vertex normals are specified in the obj file, but have the opposite sign to the normal indicated by the face winding order. If they both exist, they both need to agree.



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sixus1 posted Fri, 26 August 2005 at 9:41 AM

Interesting...I hope that we still have the problem obj laying around. If we do, I'll let you know the results. --Rebekah--


ockham posted Fri, 26 August 2005 at 4:09 PM

I've noticed that P6 has a serious problem with one-sided surfaces with holes in them. I had a swimming pool scene, with a lawn that was a one-sided grid with a hole for the pool. No matter how I flipped the normals, in Amapi or in the Poser grouping tool, it just wouldn't take a color. Finally I made it two-sided (like a thin box) and P6 condescended to apply colors. It's possible that a dress, especially if it was built the dynamic way, has the same problem...? One-sided surface with a hole for the neck?

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an0malaus posted Fri, 26 August 2005 at 5:44 PM

@ockham, not sure whether you created the grid in Amapi, but here's a render of the second simplest possible, single sided plane with hole (square; simplest would be triangular). I hacked it together by hand based on the P4 single sided square prop which is a 4 vertex, single facet square. Here's the obj file contents. v -0.050000001 0 0 v 0.050000001 0 0 v 0.050000001 0.1 0 v -0.050000001 0.1 0 v -0.016666667 0.033333333 0 v 0.016666667 0.033333333 0 v 0.016666667 0.066666667 0 v -0.016666667 0.066666667 0 vt 0 0 vt 0 1 vt 1 0 vt 1 1 vt 0.33333333 0.33333333 vt 0.33333333 0.66666667 vt 0.66666667 0.33333333 vt 0.66666667 0.66666667 g surround fo 1/1 2/3 6/7 5/5 fo 2/3 3/4 7/8 6/7 fo 3/4 4/2 8/6 7/8 fo 4/2 1/1 5/5 8/6 I textured it in P6 with a small grass pattern jpeg as a 2D image node in the Diffuse channel. Renders no problem. I'd be interested to see the grid with hole object for comparison. Did you try UVMapper on it?



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sixus1 posted Fri, 26 August 2005 at 6:13 PM

Attached Link: http://www.Sixus1Media.com/GG-Mask.zip

Here is the OBJ that I was speaking of...and it wouldn't render in P6. I was going to go with the one-sided and a hole theory. Any other ideas ? --Rebekah--

an0malaus posted Fri, 26 August 2005 at 6:19 PM

Here's a Dr Geep style kWord picture [sans N.S.G. ;-) ]



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an0malaus posted Fri, 26 August 2005 at 6:56 PM

Ummm... I guess I should clarify that I'm running P6 SR1 on Mac OS X 10.4.2, so it's entirely possible that the problems others see on the PC version do not happen on the Mac, and vice versa. I had no trouble at all rendering your mask Rebekah. I'll post a couple of screen shots as well as the render here. The obj file has unix line termination and I'm not used to seeing the empty group termination: ... f 1136/1040 1135/1039 1832/1717 # 1757 faces g but other than that and redundant z coordinates on the texture vertices, I didnt see a problem with the file.



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an0malaus posted Fri, 26 August 2005 at 6:59 PM

Here are the import options (none) I chose when loading the mask. If there was a problem with normals, I didn't want Poser trying to fix them.



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an0malaus posted Fri, 26 August 2005 at 7:02 PM

Here are the material settings I used. Virtually the simplest possible image mapped texturing possible.



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an0malaus posted Fri, 26 August 2005 at 7:05 PM

UVMapper didn't turn up it's nose at the object file either.



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an0malaus posted Fri, 26 August 2005 at 7:12 PM

Unless there's some strangeness with the texture or material settings you're trying to use Rebekah, I'm stumped, sorry. I did think to look at the end of the obj file and it does contain a line terminator at the end. I remember there being some problems with meshes failing to load properly if there was no line termination at the end of the file, but that doesn't seem to be the problem here. You might try removing the g on its own on the last line and finish the file with a blank line to see if that makes a difference.

Message edited on: 08/26/2005 19:17



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sixus1 posted Fri, 26 August 2005 at 9:25 PM

I imported the obj into Poser, same settings. I rendered it without any additional material settings. Pure black from front and back. I do remember that it would render differently with ambience settings cranked up. I will mess around with it some more. I just wanted to know what caused in case we ran across it again. --Rebekah--


ockham posted Fri, 26 August 2005 at 10:48 PM

Rebekah, here's your mask from the zip, as seen in P6 on Windows. Preview, then rendered in Firefly, then after adding a color. Looks fine; doesn't have the same problem I was seeing with my terrain stuff. Note: The OBJ refers to a MTL file, but the MTL file isn't in the ZIP. Poser didn't complain about this. Could it be that your MTL file *itself* is causing the problem?

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sixus1 posted Sat, 27 August 2005 at 3:03 AM

Wierd. I need to check and make sure that I have all of the updates and patches installed. --Rebekah--


ockham posted Sat, 27 August 2005 at 9:44 AM

Have you tried putting the MTL file outside the same folder so the OBJ won't find it?

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