Leroy Whetstone <lrw### [at] joplincom> wrote:
> Hi!
>   I haven't played with DF3 files for awhile. I did write a little
> program to covert an heightfeild TGA file(255 color) into a DF3 file by
> slicing the heightfeild into DF3 sections. Each section repersents an
> height, only where the hieght of the feild is greater than the section
> height is the voxel changed else it's zero. So there is a lot of zeros.
>
> I went through some of these DF3 files and checked out all the
> interpolate values using
>   POV version 3.6.1.icl8.win32 on my Win98
> and had no troubles. So I don't think zeros is the problem.
>
> Haven't use 'Pod's tga2df3' so I cann't comment on its use.
>
> But, I may be able to help out some.
>   First: Did you run the DF3 examples that came with POV?
>         If you have and they work Ok, then we know that there is no bug.
>          If not then we have a bug with your POV version or Win problem.
>   Second: Do you know for sure what is in the DF3 file you make?
>           That is can you read byte by byte what's on the DF3?
>           This is very important. I ran into a variable problem where I
>
>           thought I was writing one thing but I was writing something
>           else.
>   Third: You mention using a Corner Voxel in your experiments.
>          A line of voxels would tell ya more.
>
> And at last if you want I could sent you some of the DF3 files I've made
> along with that progam wrote them. The program ain't finished but it
> could giv you sme ideas.
>
> Have Fun!!

Leroy;

Hello, and thank you for the reply.

First: Yes, "GALAXY.POV" uses SPIRAL.DF3, and that renders just fine. I believe
that is the only media example that uses a DF3 file; although
SCENES\TEXTURES\PATTERNS\densfile.pov also uses SPIRAL.DF3 for both a pigment
and a normal.

Second: Yes, I know absolutely for certain. I've studied various DF3's and I
feel that I understand them... it was easy to create a small 10x10x10 DF3 "by
hand". I just used notepad until I had a textfile that was exactly 1006 bytes
long: XYZ = 10x10x10 = 10x10x10 = 1000 bytes, plus 6 bytes for the header. Then
I changed the extension from .TXT to DF3, used a hex editor to fill with zeros
(or later, 01's as Alain suggested), manually edited the first 6 bytes to 00 0A
00 0A 00 0A to create the header, and I had a blank 10x10x10 .DF3 file. I used a
hex editor to impose a voxel for testing... the offset would be X + (Y*10) +
(Z*10*10), assuming XYZ range 0 to 99. I filled the voxel location with FF (and
other values for experiments). I've experimented with setting other voxels and
intensities. In the subgroup POV Ray Binaries -> images, Alain made an
additional observation; he verifies aopparantly that he also got the error I
was getting with POVRay 3.6.1, but that the error is NOT in 3.7 (beta).

Third: I agree... a line of voxels might tell me more or, who knows? Might even
get rid of the error. Maybe it only happens when voxels are isolated and in or
near a corner, edge or face. I've never seen anyone report errors when they
uses .DF3s for, say, clouds. So maybe "busy" DF3's have no problem.

So... all in all, apparantly the problem rests in the version... since Alain
reports that 3.7 (beta) does not show this error. It might also be that I am
using the *64 bit* version of 3.6.1; if 32 bit code is improperly mixed with 64
bit code, maybe that is the source of the problem; but I expect that development
for 3.6.1 is expired, the development group is concentrating on 3.7 right now.

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