LDraw snapshots coming up empty

[Ber]

I have recently installed the LDraw AIOI installer, and trying to get started with it. 

I have a model open in LDView, and it is looking good. I then try to use the snapshot function to get a png file render of the model, but the resulting file is coming up as empty/black.

I'm highly proficient with computers, but new to everything LDraw. I've tried to find a troubleshooting guide or a forum post of someone else experiencing this problem before, to fix the problem myself, but come up blank.

So I'm hoping can someone here help me out. Any suggestions what might be configured wrong, or I'm doing wrong, etc?

[Leonardo Gonzalez]

Hello there,

Some basic questions:

1. What Operating System are you using?
   
2. What version of LDview are you using? (You can find the version on the LDview menu > Help >About LDview)
   
3. Have you tried any other model and does it behaves the same? (The LDraw-AIOI comes with a few models to try)
   

[Ber]

Hello there,

Some basic questions:

1. What Operating System are you using?
   
2. What version of LDview are you using? (You can find the version on the LDview menu > Help >About LDview)
   
3. Have you tried any other model and does it behaves the same? (The LDraw-AIOI comes with a few models to try)
   

Hi Leonardo,

Thanks for responding!

1. Windows 10 (Home, 64bit, Version 1909)
2. LDView 4.3 (x86) (27 Jan, 2018)
3. Yes, I've tried a number of models, and they all result the same, a 2-10kb black/empty png file. (I have tried 4349 - Bird, 4349 - Dragon Fly, 20015 - Alligator, and 10243 Parisian Restaurant)

I've attached an example black snapshot.

I did also receive one error message during the install of AIOI, I am not sure if it is related (as I'm not sure if LDView uses POV-Ray), but I have added it just in case.

[Leonardo Gonzalez]

So you can see the model and rotate it, but when it comes time to do the snapshot it doesn't show in the file.

What options are checked in the "save snapshot" dialog window? (where you enter the image name)

[Ber]

So you can see the model and rotate it, but when it comes time to do the snapshot it doesn't show in the file.

What options are checked in the "save snapshot" dialog window? (where you enter the image name)

Yes, that's right, in the LDView window I can see and rotate the model.

At the moment in the Save Snapshot dialog I have none of the checkboxes selected.

I have tried with these turned on, in various combinations:
- Save snapshot series (file name then ends in 01)
- Don't use Pixel Buffer
- Transparent background
- Auto-crop
- Save image with specific size

The output file is always 100% black / transparent for any combination of these options I have tried.

I tried saving as a jpg once (still black), otherwise always saving as png.

I have not tried the checkbox 'All Steps'.

[Roland Melkert]

The output file is always 100% black / transparent for any combination of these options I have tried.

This is probably an OpenGL issue, are you using the latest drivers (usually OpenGL 4.x).

You could try LDCad as it also uses OpenGL for the export to png.

Just load your model and press alt+e, and choose OpenGL view export. The png will be saved in the same folder as the loaded model.

If that one is also all black then this is most definitely a driver issue.

[Travis Cobbs]

I have recently installed the LDraw AIOI installer, and trying to get started with it. 

I have a model open in LDView, and it is looking good. I then try to use the snapshot function to get a png file render of the model, but the resulting file is coming up as empty/black.

I'm highly proficient with computers, but new to everything LDraw. I've tried to find a troubleshooting guide or a forum post of someone else experiencing this problem before, to fix the problem myself, but come up blank.

So I'm hoping can someone here help me out. Any suggestions what might be configured wrong, or I'm doing wrong, etc?

I can't think of anything that would cause that, but one thing you can try is to install LDView 4.4 Beta 1 and see if that fixes the problem. Also, I would suggest trying the 64-bit version of LDView 4.4 Beta 1 (LDView64-4400B1.exe). If that doesn't help, there is at least one more thing you can try, but it requires using the Registry Editor.

[Leonardo Gonzalez]

I am unable to replicate your error, so I have no solution to offer. Follow the advice of Roland and Travis. Otherwise, try to reinstall.

[Ber]

This is probably an OpenGL issue, are you using the latest drivers (usually OpenGL 4.x).

You could try LDCad as it also uses OpenGL for the export to png.

Just load your model and press alt+e, and choose OpenGL view export. The png will be saved in the same folder as the loaded model.

If that one is also all black then this is most definitely a driver issue.

Hi Roland! Thank you for taking the time to help me with this!

I tried exporting to png from LDCad as you suggested, and it worked! I guess that rules out a driver issue.

But I saw the export to POVRay option too, so I gave that a go. I got the .pov file, then figured out my way around POVRay to generate a 1920x1080 0.3 AA file, which looks fantastic

So LDraw still doesn't work, but maybe that doesn't matter with what you've helped me find in LDCad. Thank you again!

[Ber]

I can't think of anything that would cause that, but one thing you can try is to install LDView 4.4 Beta 1 and see if that fixes the problem. Also, I would suggest trying the 64-bit version of LDView 4.4 Beta 1 (LDView64-4400B1.exe). If that doesn't help, there is at least one more thing you can try, but it requires using the Registry Editor.

Hi Travis,

Thank you for dropping by to help me  

I tried installing the 64bit beta version you suggested. Unfortunately, I still get solid black snapshot files.

As I mentioned in my reply to Roland, the export in LDCad worked fine, (apparently suggesting OpenGL drivers are okay), if that is helpful information for you.

I am interested in getting LDView working though, happy to work with your suggestions to figure it out, and give you back any information that is helpful for you in the development of it.

I'm a sometimes software developer myself, as well as working part time in a software support helpdesk, and highly proficient in editing the Windows Registry (and not breaking it...), so don't worry about getting too technical for me

[Ber]

I am unable to replicate your error, so I have no solution to offer. Follow the advice of Roland and Travis. Otherwise, try to reinstall.

Hi Leonardo,

Thanks for trying!

It looks like I will be fine with Travis and Roland, but if you want to jump back in at any time with your thoughts, you're welcome to.

[Travis Cobbs]

Hi Travis,

Thank you for dropping by to help me  

I tried installing the 64bit beta version you suggested. Unfortunately, I still get solid black snapshot files.

As I mentioned in my reply to Roland, the export in LDCad worked fine, (apparently suggesting OpenGL drivers are okay), if that is helpful information for you.

I am interested in getting LDView working though, happy to work with your suggestions to figure it out, and give you back any information that is helpful for you in the development of it.

I'm a sometimes software developer myself, as well as working part time in a software support helpdesk, and highly proficient in editing the Windows Registry (and not breaking it...), so don't worry about getting too technical for me

I suspect that Roland was right and this is a driver problem. Bear in mind that while both LDView and LDCad use OpenGL, they do so in very different ways.

The first thing to try is to disable LDView's use of all OpenGL extensions. If this fixes the problem, you can then try to narrow down which specific extension(s) is/are causing the problem. (You definitely want LDView to be able to use as many extensions as possible.)

To disable LDView's use of OpenGL extensions, do the following:

• Run regedit
  
• Browse to HKEY_CURRENT_USER\Software\Travis Cobbs\LDView
  
• Right click on the LDView key in the tree and select New->DWORD (32-bit) Value
  
• Rename the new value to IgnoreAllOGLExtensions
  
• Edit the value and set it to 1
  

Exit LDView if it is running and run it again. Then open your model and save the snapshot. If this doesn't fix the problem, then I honestly have no idea what is going on. If it does fix the problem, the next step is to try to figure out which OpenGL extension is causing the problem.

To do this, edit the IgnoreAllOGLExtensions value and set it to 0. The most likely other problem extensions are FBO, PBuffer, and PixelFormat. So try creating one or more of the following DWORD registry values (in the same LDView registry key) with values of 1:

• IgnoreFramebufferObject
  
• IgnorePBuffer
  
• IgnorePixelFormat
  

To be honest, if "IgnoreAll" works, and none of the above works (even all three), then I'll be very surprised. But these are the other keys that can be set to ignore other extensions:

• IgnoreAniso
  
• IgnoreMultiDrawArrays
  
• IgnoreMultisample
  
• IgnoreMultisampleFilterHint
  
• IgnoreVAR
  
• IgnoreVBO
  

[Ber]

I suspect that Roland was right and this is a driver problem. Bear in mind that while both LDView and LDCad use OpenGL, they do so in very different ways.

The first thing to try is to disable LDView's use of all OpenGL extensions. If this fixes the problem, you can then try to narrow down which specific extension(s) is/are causing the problem. (You definitely want LDView to be able to use as many extensions as possible.)

To disable LDView's use of OpenGL extensions, do the following:

• Run regedit
  
• Browse to HKEY_CURRENT_USER\Software\Travis Cobbs\LDView
  
• Right click on the LDView key in the tree and select New->DWORD (32-bit) Value
  
• Rename the new value to IgnoreAllOGLExtensions
  
• Edit the value and set it to 1
  

Exit LDView if it is running and run it again. Then open your model and save the snapshot. If this doesn't fix the problem, then I honestly have no idea what is going on. If it does fix the problem, the next step is to try to figure out which OpenGL extension is causing the problem.

To do this, edit the IgnoreAllOGLExtensions value and set it to 0. The most likely other problem extensions are FBO, PBuffer, and PixelFormat. So try creating one or more of the following DWORD registry values (in the same LDView registry key) with values of 1:

• IgnoreFramebufferObject
  
• IgnorePBuffer
  
• IgnorePixelFormat
  

To be honest, if "IgnoreAll" works, and none of the above works (even all three), then I'll be very surprised. But these are the other keys that can be set to ignore other extensions:

• IgnoreAniso
  
• IgnoreMultiDrawArrays
  
• IgnoreMultisample
  
• IgnoreMultisampleFilterHint
  
• IgnoreVAR
  
• IgnoreVBO
  

Hi again

Thanks for giving me these steps to try!

So, my starting point for testing the registry settings was using the latest 64-bit you recommended I download. Since my last post, I have also tried installing the whole LDraw package on a second computer, a desktop gaming computer. All this talk about OpenGL, I figured a better video card than on my basic laptop might make a difference. What I found on the desktop was, same problem! black output files.

However, when I tried the registry fixes, they worked on both the laptop and desktop, but each needed a different 'Ignore' setting!

Desktop:
IgnoreAllOGLExtensions = 1
Result: good png

IgnoreAllOGLExtensions = 0
IgnoreFramebufferObject = 1
Result: black png

IgnoreAllOGLExtensions = 0
IgnorePBuffer = 1
Result: black png

IgnoreAllOGLExtensions = 0
IgnorePixelFormat = 1
Result: good png

laptop:
IgnoreAllOGLExtensions = 1
Result: good png

IgnoreAllOGLExtensions = 0
IgnoreFramebufferObject = 1
Result: black png

IgnoreAllOGLExtensions = 0
IgnorePBuffer = 1
Result: good png

IgnoreAllOGLExtensions = 0
IgnorePixelFormat = 1
Result: black png


So, OpenGL really not behaving for LDView! But I have a working solution for LDView on both computers now, thank you.

I hope my results are helpful for you. If you would like any other info or testing from me to help you make use of my test results, let me know and I'll be happy to help.

[Travis Cobbs]

Hi again

Thanks for giving me these steps to try!

...

So, OpenGL really not behaving for LDView! But I have a working solution for LDView on both computers now, thank you.

I hope my results are helpful for you. If you would like any other info or testing from me to help you make use of my test results, let me know and I'll be happy to help.

Thanks. Because LDView uses such old OpenGL functionality (OpenGL 1.0, when OpenGL 2.0 was released in 2004), I think it has a tendency to expose bugs in graphics drivers that other programs don't. I can't be sure that LDView itself doesn't have bugs in this code, but I cannot fix a problem that I cannot reproduce. (I've looked at my code, and haven't found the source of your problems.)

It is definitely good to know that the PixelFormat and PBuffer extensions are causing you problems, because it makes it potentially easier for future people that have the same problem. Given that (as far as I know) snapshot saves work for most LDView users, I'm amazed that you have two computers that have two different problems with snapshot saves.

The good news is that I don't think having those particular extensions disabled will adversely affect the rest of LDView's functionality.

[Travis Cobbs]

Thanks. Because LDView uses such old OpenGL functionality (OpenGL 1.0, when OpenGL 2.0 was released in 2004), I think it has a tendency to expose bugs in graphics drivers that other programs don't. I can't be sure that LDView itself doesn't have bugs in this code, but I cannot fix a problem that I cannot reproduce. (I've looked at my code, and haven't found the source of your problems.)

It is definitely good to know that the PixelFormat and PBuffer extensions are causing you problems, because it makes it potentially easier for future people that have the same problem. Given that (as far as I know) snapshot saves work for most LDView users, I'm amazed that you have two computers that have two different problems with snapshot saves.

The good news is that I don't think having those particular extensions disabled will adversely affect the rest of LDView's functionality.

The newly announced LDView 4.4 Beta 2 contains check boxes to disable these things via the UI. If you run that release, the appropriate check box should already be checked based on your manual registry editing.

[Ber]

The newly announced LDView 4.4 Beta 2 contains check boxes to disable these things via the UI. If you run that release, the appropriate check box should already be checked based on your manual registry editing.

I missed this reply previously, and just saw it.

Thanks for this, that sounds great! I will check it out

edit: I've installed the new version, looks good! I can confirm that the checkbox is checked matching my manual registry edit