OSMesa LDview Crash

[Orion Pobursky]

The OSMesa LDview is crashing with the error "Segmentation Fault" when trying to render the attached file. This file renders fine on my Windows machine. Any help is appreciated.

[Orion Pobursky]

The OSMesa LDview is crashing with the error "Segmentation Fault" when trying to render the attached file. This file renders fine on my Windows machine. Any help is appreciated.

It rendered without error when I removed the embedded texture file.

[Orion Pobursky]

I found the bug.

No I didn't

I am, however, starting to think that this is most likely related to the server and not LDView

[Orion Pobursky]

After some more troubleshooting:

If I render the part (168285a.dat) without it being an MPD, it renders without error. The seg fault only happens with the MPD and happens regardless of whether or not the DATA file is present.

[Chris Böhnke]

Uh... I wasn't expecting this part to cause that much trouble.

Not really sure if it helps, but I also realized some issues when trying to import this into Stud.io. I tried again with an older version without the texture and the same happened. Maybe this is an issue with the primitives?

Here's the earlier version:

  168285a_NoTexmap.dat (Size: 37.5 KB / Downloads: 0)

Whilst looking for TexMap examples, I also discovered a little bug with an older part (https://library.ldraw.org/parts/10820). It looks fine on the PT, but if I look at it in my local LDView installation, one segment is off:
   

Maybe there is a connection?

Sorry for the mess,
Chris

[Chris Böhnke]

If I understand the Wikipedia article about "Segmentation Fault" correctly, it means something tries to access memory areas that it shouldn't.

Maybe the file is too large, creating a sort of overflow or something?

When I tried to send you the image via PM, it wouldn't allow me, telling that it exceeds the allowed bit size, which sounds similar.

EDIT:
I am not entirely familiar with how the Texture Map Extension is actually implemented, but is it an issue this file uses quite a large number of lines within a single TexMap command? Most files I found thus far have 1-4 only.

[Orion Pobursky]

If I understand the Wikipedia article about "Segmentation Fault" correctly, it means something tries to access memory areas that it shouldn't.

Maybe the file is too large, creating a sort of overflow or something?

When I tried to send you the image via PM, it wouldn't allow me, telling that it exceeds the allowed bit size, which sounds similar.

EDIT:
I am not entirely familiar with how the Texture Map Extension is actually implemented, but is it an issue this file uses quite a large number of lines within a single TexMap command? Most files I found thus far have 1-4 only.

If it were a solely a memory issue then fault would occur regardless of how the file is structured. Since it only happens if I roll the part up into an MPD there's something else in play.

[Orion Pobursky]

I am not entirely familiar with how the Texture Map Extension is actually implemented, but is it an issue this file uses quite a large number of lines within a single TexMap command? Most files I found thus far have 1-4 only.

That's it. If I replace the front lines with the 3 lines that make up the back side, no fault. 

I test further, looks like the limit is 36 lines.

[Orion Pobursky]

I thought I had it nailed down to line count but this proved to be false. 

More tinkering revealed that the TEXMAP portion of the part *must* be the first geometry in the part. Once I moved the TEXMAP to the beginning of the part, the image generated fine. This is not required by spec but will prevent the image creation issue that has been happening.