[SOLVED] Raytracing Tutorial ... failed

[Tilli]

I did not try a home-folder location because I didn't want it there, and to be honest, if something only works when the home-folder's specified, then that sounds like a hardcoded cause for concern right there (see worries above).

No it's not that. POV-Ray (used through FreeCAD or as a standalone) doesn't like non-ASCII characters in the path. That is why i said just do the test by using the home folder. To confirm if it is working in general or not.

I explicitly created this root-level folder specifically for such tasks, and set appropriately liberal permissions.

Likely this is the culprit yes. Something isn't set up correctly.

So I've now tried it for you, specifying it into the home folder's Desktop, and the (non-)result was exactly the same.

You also seem to doubt ASCII characters. Erm, looking past the format-mangling caused by phpBB's apparent inability to combine both monospace-font and code tags, they sure all look like ASCII-printables to me :

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echo  '/FreeCAD_Output/renderedoutput001.png'   |   od -tdCac -w16

0000000   47   70  114  101  101   67   65   68   95   79  117  116  112  117  116   47
                    /    F    r    e    e    C    A    D    _    O    u    t    p    u    t    /
                    /    F    r    e    e    C    A    D    _    O    u    t    p    u    t    /
0000020  114  101  110  100  101  114  101  100  111  117  116  112  117  116   48   48
                     r    e    n    d    e    r    e    d    o    u    t    p    u    t    0    0
                     r    e    n    d    e    r    e    d    o    u    t    p    u    t    0    0
0000040   49   46  112  110  103   10
                   1    .    p    n    g   nl
                   1    .    p    n    g   \n
0000046

I wholeheartedly agree that the problem most likely stems from "something isn't set up correctly" but my suspicion is that it's something been omitted from the Tutorial. A pre-requisite..? An assumption..?

For example, just off the top of my head, I'm now wondering whether you're all assuming modern fast hardware with current OpenGL or suchlike, you know, those component type things that are easily overlooked, and which haven't actually been listed as a pre-requisite..?

FWIW :

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Graphics:  Card: Intel 4 Series Integrated Graphics Controller
           Display Server: X.Org 1.18.4 drivers: intel (unloaded: fbdev,vesa) Resolution: 1280x1024@75.02hz
           GLX Renderer: Mesa DRI Intel Q45/Q43 GLX Version: 2.1 Mesa 17.2.4

Thanks anyway.

[triplus]

Hi @Tilli.

There needs to be some mutual level of respect involved. I don't feel that ATM. Therefore better if you try to resolve this one yourself for now. If you won't be able to do it but would still like to do it. Come back to us in a couple of days and we can investigate further.

[Tilli]

Hi @Tilli.

There needs to be some mutual level of respect involved. I don't feel that ATM. Therefore better if you try to resolve this one yourself for now. If you won't be able to do it but would still like to do it. Come back to us in a couple of days and we can investigate further.

Hi @triplus

You sound upset. Therefore I offer profuse apologies for any offence caused. No personally-directed negative vibes were intended.

PM sent.

[triplus]

Fair enough.

If you open a terminal (Linux distribution one and not FreeCAD related):

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povray

Does it complain about configuration file missing?

[salp]

FWIW, the linux install of povray does not seem to install the povray config files in the user home directory and it does not read the system config files.

The system wide config files are located in /etc/povray/3.7/ directory, this is simply fixed by creating the directory in the user directory and copy the config files.

mkdir /home/<username>/.povray/3.7
cp /etc/povray/3.7/* /home/<username>/.povray/3.7/

now when you run povray it will not complain about missing config file.

Hope that helps.

[Tilli]

. . .

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povray

Does it complain . , ,

. . . the linux install of povray does not seem to install . . .

Yes indeed @triplus, in Konsole it did complain :

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povray: cannot open the user configuration file /home/tilli/.povray/3.7/povray.conf: No such file or directory

And so I followed your suggestion @salp for creating these missing local config files where they should be.

Rigorously repeating the steps in the Raytracing_tutorial unfortunately gave exactly the same (non-)result.

However...

Your suspicions surrounding already-known issues with Linux povray installations were the useful tipping-point, prompting me to explore that direction. Landing on an introductory povray tutorial got me thinking about the support files it mentioned.

In Konsole a quick systemwide search indicated they were not present.

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tree -aif /   |   grep --colour -iE '(/povray.*/|glass.inc)'

It seems that the Ubuntu-based Linux Mint install of povray does not automatically include these support files, instead only mentioning "povray-includes" in the description as "highly recommended."

Installing (actually as part of "povray-examples") the package "povray-includes" seems to be the final missing piece of the puzzle. Because now, repeating the Raytracing_tutorial finally gave a pop-up window with a rendered image, and it did so into my specially-created /FreeCAD_Output folder without issue or complaint.

Which means it looks like together we solved it.

I will have to add a little to the wiki, extra info about Linux+povray installations, based on what we've learnt.

Once again, a big Thank You for all your attention, your input, and your patience.

[NormandC]

It seems that the Ubuntu-based Linux Mint install of povray does not automatically include these support files, instead only mentioning "povray-includes" in the description as "highly recommended."

In Ubuntu, povray-includes is listed as "Recommends:" for the povray package. Packages identified as "Recommends:" are automatically installed by default. The setting is called "Treat recommended packages as dependencies" and I've only found it listed in Synaptic's preferences. It is not listed anywhere in Software & Updates. So the user needs to purposely disable this setting, and since Synaptic is no longer installed by default, we can assume that most users will never disable it.

Are you saying that it's not the case on Linux Mint? I'm trying hard to understand their reasoning on this.

[triplus]

Installing (actually as part of "povray-examples") the package "povray-includes" seems to be the final missing piece of the puzzle. Because now, repeating the Raytracing_tutorial finally gave a pop-up window with a rendered image, and it did so into my specially-created /FreeCAD_Output folder without issue or complaint.

Which means it looks like together we solved it.

Good to hear that.

I will have to add a little to the wiki, extra info about Linux+povray installations, based on what we've learnt.

Thanks.

[Tilli]

It seems that the Ubuntu-based Linux Mint install of povray does not automatically include these support files, instead only mentioning "povray-includes" in the description as "highly recommended."

In Ubuntu, povray-includes is listed as "Recommends:" for the povray package. Packages identified as "Recommends:" are automatically installed by default. The setting is called "Treat recommended packages as dependencies" and I've only found it listed in Synaptic's preferences. It is not listed anywhere in Software & Updates. So the user needs to purposely disable this setting, and since Synaptic is no longer installed by default, we can assume that most users will never disable it.

Are you saying that it's not the case on Linux Mint? I'm trying hard to understand their reasoning on this.

Ooh. Erm. Tricky question. "Pass..."

It's ironic that this might even be a perfect example of my having gone off-piste in the past and it coming back to bite me, which is exactly what I was fretting about a few posts ago regarding the non-listed Addons/Macros.

Bowie famously sang "Ch-ch-ch-changes..." and there've been far too many here it would seem. I had originally composed yet another much longer reply explaining loads about the "route to now." In the end I've deleted it all as pointless noise.

Suffice to say, in the two or three years I've been using Linux Mint, I've upgraded -- as distinct from a fresh install, in which prefs go default -- the OS version once or twice. The developers too definitely have changed their installer/updater design and policies quite a lot. On top of that, following various security concerns and (off-piste) suggestions I encountered, I know I have indeed altered preferences locally at times.

Unfortunately the exact what and when of all this is lost to memory.

Interesting you should mention Synaptic, I do have Synaptic Package Manager installed here. Given my internet situation, two of the first changes I always make after an OS install are the updater's auto-download settings and the package-manager's keepcache behaviour. From years of yum/fedora I remember being a bit confused and blunderbussy after switching to apt/ubuntu. While trying to firstly "Find..." and then "Control..." foobar in the unfamiliar apt/ubuntu landscape I'll admit there was a fair bit of thrashing-about, and I think Synaptic was part of that period.

I just launched it, and the preference "Consider recommended packages as dependencies" was indeed un-checked. I do not remember whether that was my doing, nor when.

Toggling it, clicking "Apply" then running a timestamp-search "find / -newermt '1 minute ago'" (several -prunes omitted here) revealed that two files had just been modified.

/etc/apt/apt.conf.d/99synaptic contains the single line :

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APT::Install-Recommends "true";

/root/.synaptic/synaptic.conf contains many other settings, including the line :

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Install-Recommends "1";

I do not know why there's both synaptic.conf and 99synaptic apparently duplicating the setting for Recommends. Anyway, for the reasons hinted earlier, I've GUI-toggled it back to unchecked and after clicking "Apply" these two files both changed (to "false" and "0" respectively).

I suppose only someone doing a series of fresh installs today, perhaps in a virtual guest, could say what the various defaults actually have been and are now. Unfortunately with the internet-access I (barely) have and other resource-limitations under which I struggle, I'm unable to be that tester and unable to establish exactly what's what.

So, it's a case of sorry @NormandC, I can't easily say one way or the other. Hopefully you see why.

The important thing is we found a reason, a potential gotcha, and this can be flagged-up in the docs.

TL;DR : Linux Mint have definitely changed both their GUI application and their default policies throughout my time using it; and I myself have quite possibly also changed preferences in this area too, but I don't know the full what and when.

[Tilli]

I will have to add a little to the wiki, extra info about Linux+povray installations, based on what we've learnt.

Thanks.

I've added an extra line to the pre-requisites section of the wiki page. Adding content to the deemed-definitive Documentation is a much bigger responsibility than just being a typo-cleanup wiki-elf. Therefore, please would one of you project guardians check its suitability.

Thanks.