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digitalmars.D.learn - Loading assimp

reply Dlearner <daz20 msn.com> writes:
I'm trying to use assimp to load models in a program.  I see the 
Derelict binding is for version 3.3, but the assimp site has no 
binaries for this, just source.  So I try to use version 3.1.1 
and I get this error:

derelict.util.exception.SymbolLoadException ..\..\AppData\Roaming\dub\packages\derelict-util-2.0.6\derelict-util\source\derelict\u
il\exception.d(35): Failed to load symbol aiReleaseExportFormatDescription from
shared library assimp.dll

Is this a version problem that I need 3.3 for?  If so, I don't 
know how to build the .dll since I'm still new to programming.  
Please send help!  :)
Jan 09 2017
parent reply Mike Parker <aldacron gmail.com> writes:
On Monday, 9 January 2017 at 18:13:03 UTC, Dlearner wrote:

 I'm trying to use assimp to load models in a program.  I see 
 the Derelict binding is for version 3.3, but the assimp site 
 has no binaries for this, just source.  So I try to use version 
 3.1.1 and I get this error:

 derelict.util.exception.SymbolLoadException ..\..\AppData\Roaming\dub\packages\derelict-util-2.0.6\derelict-util\source\derelict\u
il\exception.d(35): Failed to load symbol aiReleaseExportFormatDescription from
shared library assimp.dll


Use version 1.1.1 of DerelictASSIMP3. It's implemented against 
ASSIMP 3.1.
Jan 09 2017
parent reply Dlearner <daz20 msn.com> writes:
On Tuesday, 10 January 2017 at 00:10:12 UTC, Mike Parker wrote:

 On Monday, 9 January 2017 at 18:13:03 UTC, Dlearner wrote:

 I'm trying to use assimp to load models in a program.  I see 
 the Derelict binding is for version 3.3, but the assimp site 
 has no binaries for this, just source.  So I try to use 
 version 3.1.1 and I get this error:

 derelict.util.exception.SymbolLoadException ..\..\AppData\Roaming\dub\packages\derelict-util-2.0.6\derelict-util\source\derelict\u
il\exception.d(35): Failed to load symbol aiReleaseExportFormatDescription from
shared library assimp.dll


 Use version 1.1.1 of DerelictASSIMP3. It's implemented against 
 ASSIMP 3.1.


A-haa, thank you!
Jan 10 2017
parent reply Dlearner <daz20 msn.com> writes:
Need to rez this thread because I ran into a wall.  Two little 
things:

1) Can't seem to get the Importer class to work ("undefined 
identifier 'Importer' ", etc), and
2) GetTexture and GetTextureCount for aiMaterial don't seem to 
work
(source\model.d(105,28): Error: no property 'GetTextureCount' for 
type 'aiMaterial*'
source\model.d(107,6): Error: no property 'GetTexture' for type 
'aiMaterial*')

There are some const issues, too, but I can hack around them.  
Does anyone have any experience with these?
Jan 29 2017
parent reply Dlearner <daz20 msn.com> writes:
I came back to this project and realised my mistakes (Importer is 
a class for the C++ API, and we're using the C API).
So I fixed all my errors, but now I get an access violation.
As far as I can tell, it seems to be an issue with 
`aiGetMaterialTexture`.  It is meant to return an aiString with a 
filename (default value of "$texture.png"), I believe.  But I get:

aiString(13, x"67 6C 61 73 73 5F 64 69 66 2E 70 6E 67 00 FF FF FF 
... FF"c)
[shortened for brevity]

I'm meant to add this on to a directory string so I can load an 
image, but obviously this wouldn't work.

I thought it might be a problem with converting from D-strings to 
C-strings.  I sent a string to `aiImportFile` as 
`toStringz(path)`.
I tested this with some writeln debugging:

```
auto temp = path.toStringz;
writeln("toStringz: ", temp);
writeln("string: ", temp.to!string);
```

This gave:
toStringz: 4770B6
string: Models/Nanosuit/nanosuit.obj

So maybe this is a problem with using aiStrings?  I'm quite 
confused.  Sorry if this is more of an assimp question than a D 
question, but I don't know if it's me misusing D language 
features or not.
Mar 26 2017
parent reply ag0aep6g <anonymous example.com> writes:
On Sunday, 26 March 2017 at 10:34:21 UTC, Dlearner wrote:

 I came back to this project and realised my mistakes (Importer 
 is a class for the C++ API, and we're using the C API).
 So I fixed all my errors, but now I get an access violation.
 As far as I can tell, it seems to be an issue with 
 `aiGetMaterialTexture`.  It is meant to return an aiString with 
 a filename (default value of "$texture.png"), I believe.  But I 
 get:

 aiString(13, x"67 6C 61 73 73 5F 64 69 66 2E 70 6E 67 00 FF FF 
 FF ... FF"c)
 [shortened for brevity]


The data is "glass_dif.png", followed by a null terminator, 
followed by a bunch of 0xFFs. 13 is the length of 
"glass_dif.png". Judging from the definition of aiString [1], the 
0xFFs are just unused space. So, this looks good.


 I'm meant to add this on to a directory string so I can load an 
 image, but obviously this wouldn't work.


To convert an aiString to a D string, it should be possible to 
slice the data with the length:

     aiString x;
     const(char)[] y = x.data[0 .. x.length];

You have to be cautiots of lifetime requirements, of course. If 
needed, you can make a copy with dup (mutable copy) or idup 
(immutable copy):

     const(char)[] y = x.data[0 .. x.length].dup;
     string z = x.data[0 .. x.length].idup;


[1] http://www.assimp.org/lib_html/structai_string.html
Mar 26 2017
parent reply Dlearner <daz20 msn.com> writes:
On Sunday, 26 March 2017 at 11:10:55 UTC, ag0aep6g wrote:

 On Sunday, 26 March 2017 at 10:34:21 UTC, Dlearner wrote:

 I came back to this project and realised my mistakes (Importer 
 is a class for the C++ API, and we're using the C API).
 So I fixed all my errors, but now I get an access violation.
 As far as I can tell, it seems to be an issue with 
 `aiGetMaterialTexture`.  It is meant to return an aiString 
 with a filename (default value of "$texture.png"), I believe.  
 But I get:

 aiString(13, x"67 6C 61 73 73 5F 64 69 66 2E 70 6E 67 00 FF FF 
 FF ... FF"c)
 [shortened for brevity]


 The data is "glass_dif.png", followed by a null terminator, 
 followed by a bunch of 0xFFs. 13 is the length of 
 "glass_dif.png". Judging from the definition of aiString [1], 
 the 0xFFs are just unused space. So, this looks good.


 I'm meant to add this on to a directory string so I can load 
 an image, but obviously this wouldn't work.


 To convert an aiString to a D string, it should be possible to 
 slice the data with the length:

     aiString x;
     const(char)[] y = x.data[0 .. x.length];

 You have to be cautiots of lifetime requirements, of course. If 
 needed, you can make a copy with dup (mutable copy) or idup 
 (immutable copy):

     const(char)[] y = x.data[0 .. x.length].dup;
     string z = x.data[0 .. x.length].idup;


 [1] http://www.assimp.org/lib_html/structai_string.html


Ahh this did help!  I practically followed your advice, then 
fixed a somewhat unrelated range violation, and got a similar 
"object.Error (0): Access Violation".  But in the console I got:
filename: Models/Nanosuit/glass_dif.png
filename: Models/Nanosuit/leg_dif.png
filename: Models/Nanosuit/leg_showroom_spec.png
filename: Models/Nanosuit/hand_dif.png
filename: Models/Nanosuit/hand_showroom_spec.png
filename: Models/Nanosuit/arm_dif.png
filename: Models/Nanosuit/arm_showroom_spec.png
filename: Models/Nanosuit/helmet_diff.png

About half the textures seem to load fine.  Some progress!
Mar 26 2017
parent reply Dlearner <daz20 msn.com> writes:
On Sunday, 26 March 2017 at 12:40:42 UTC, Dlearner wrote:


 ...
 About half the textures seem to load fine.  Some progress!


I don't know why, but when I get to the 8th texture, the filename 
has some garbage attached.

SDL_Surface* surface = IMG_Load(filename.ptr);
     if (surface is null) {
         writeln("surface is null: ", to!string(IMG_GetError()));
     } else {
         writeln(filename);
     }

 From console:
surface is null: Couldn't open Models/Nanosuit/helmet_diff.pngÇ2ÿ

I'm assuming the previous textures didn't experience this, but I 
have no idea what could be the problem here, especially as the 
filename seems fine when I writeln it.
:(
Mar 26 2017
parent reply ag0aep6g <anonymous example.com> writes:
On 03/26/2017 11:31 PM, Dlearner wrote:

 SDL_Surface* surface = IMG_Load(filename.ptr);
     if (surface is null) {
         writeln("surface is null: ", to!string(IMG_GetError()));
     } else {
         writeln(filename);
     }

 From console:
 surface is null: Couldn't open Models/Nanosuit/helmet_diff.pngÇ2ÿ

 I'm assuming the previous textures didn't experience this, but I have no
 idea what could be the problem here, especially as the filename seems
 fine when I writeln it.
 :(


How do you construct `filename`? Looks like it's not properly 
null-terminated.

If you followed my (short-sighted) `dup` advice, that doesn't do 
null-termination. Since the original strings are null-terminated, just 
slicing one more character should do the trick. I'd put an assert that 
verifies that the last character is '\0'.

I.e.:
----
string z = x.data[0 .. x.length + 1].idup;
assert(z[$ - 1] == '\0');
----

Generally, don't pass just the pointer of a string unless you know for 
sure that it's properly null-terminated.

If you're using a slice directly, without `dup`-ing, then the original 
aiString would seem to be broken already.
Mar 26 2017
parent reply Dlearner <daz20 msn.com> writes:
On Sunday, 26 March 2017 at 21:52:42 UTC, ag0aep6g wrote:

 On 03/26/2017 11:31 PM, Dlearner wrote:

 SDL_Surface* surface = IMG_Load(filename.ptr);
     if (surface is null) {
         writeln("surface is null: ", 
 to!string(IMG_GetError()));
     } else {
         writeln(filename);
     }

 From console:
 surface is null: Couldn't open 
 Models/Nanosuit/helmet_diff.pngÇ2ÿ

 I'm assuming the previous textures didn't experience this, but 
 I have no
 idea what could be the problem here, especially as the 
 filename seems
 fine when I writeln it.
 :(


 How do you construct `filename`? Looks like it's not properly 
 null-terminated.

 If you followed my (short-sighted) `dup` advice, that doesn't 
 do null-termination. Since the original strings are 
 null-terminated, just slicing one more character should do the 
 trick. I'd put an assert that verifies that the last character 
 is '\0'.

 I.e.:
 ----
 string z = x.data[0 .. x.length + 1].idup;
 assert(z[$ - 1] == '\0');
 ----

 Generally, don't pass just the pointer of a string unless you 
 know for sure that it's properly null-terminated.

 If you're using a slice directly, without `dup`-ing, then the 
 original aiString would seem to be broken already.


Ahh you were absolutely right.  I concatenated a '\0' and it 
worked.  Silly me!
Most of the textures loaded and a really broken model appears, 
but I'm guessing that's a result of trying to follow along with a 
tutorial written for C++ in D.
Thank you for your help.  I really appreciate it.  :)
Mar 27 2017
parent reply Eric_DD <invalid null.null> writes:
I am trying to use a newer version of Assimp.
I have found a assimp-vc140-mt.dll (v3.3.1) which I renamed to 
assimp.dll

When running my executable it throws a 
derelict.util.exception.SharedLibLoadException:

"Failed to load one or more shared libraries:
         assimp.dll - %1 is not a valid Win32 application.
         Assimp64.dll - The specified module could not be found"

Any idea what's going on? Are 64bit dlls not supported?
Sep 28 2021
next sibling parent reply russhy <russhy gmail.com> writes:
On Tuesday, 28 September 2021 at 16:30:09 UTC, Eric_DD wrote:

 I am trying to use a newer version of Assimp.
 I have found a assimp-vc140-mt.dll (v3.3.1) which I renamed to 
 assimp.dll

 When running my executable it throws a 
 derelict.util.exception.SharedLibLoadException:

 "Failed to load one or more shared libraries:
         assimp.dll - %1 is not a valid Win32 application.
         Assimp64.dll - The specified module could not be found"

 Any idea what's going on? Are 64bit dlls not supported?


try to rename it to Assimp64.dll
Sep 28 2021
parent reply Eric_DD <invalid null.null> writes:
On Tuesday, 28 September 2021 at 19:59:09 UTC, russhy wrote:

 On Tuesday, 28 September 2021 at 16:30:09 UTC, Eric_DD wrote:

 I am trying to use a newer version of Assimp.
 I have found a assimp-vc140-mt.dll (v3.3.1) which I renamed to 
 assimp.dll

 When running my executable it throws a 
 derelict.util.exception.SharedLibLoadException:

 "Failed to load one or more shared libraries:
         assimp.dll - %1 is not a valid Win32 application.
         Assimp64.dll - The specified module could not be found"

 Any idea what's going on? Are 64bit dlls not supported?


 try to rename it to Assimp64.dll


Nah :) Already tried that. It just swaps the file names in the 
error message.
Sep 28 2021
parent russhy <russhy gmail.com> writes:
On Tuesday, 28 September 2021 at 20:09:41 UTC, Eric_DD wrote:

 On Tuesday, 28 September 2021 at 19:59:09 UTC, russhy wrote:

 On Tuesday, 28 September 2021 at 16:30:09 UTC, Eric_DD wrote:

 I am trying to use a newer version of Assimp.
 I have found a assimp-vc140-mt.dll (v3.3.1) which I renamed 
 to assimp.dll

 When running my executable it throws a 
 derelict.util.exception.SharedLibLoadException:

 "Failed to load one or more shared libraries:
         assimp.dll - %1 is not a valid Win32 application.
         Assimp64.dll - The specified module could not be 
 found"

 Any idea what's going on? Are 64bit dlls not supported?


 try to rename it to Assimp64.dll


 Nah :) Already tried that. It just swaps the file names in the 
 error message.


Derelict is kinda old anyways, to make sure we use up to date 
stuff, try to migrate to bindbc one

https://github.com/Sobaya007/bindbc-assimp

https://code.dlang.org/packages/bindbc-assimp

If i were you i'd compile the project myself, so you know what 
your DLL is

https://github.com/assimp/assimp

https://github.com/assimp/assimp/blob/master/Build.md
Sep 29 2021
prev sibling next sibling parent reply Mike Parker <aldacron gmail.com> writes:
On Tuesday, 28 September 2021 at 16:30:09 UTC, Eric_DD wrote:

 I am trying to use a newer version of Assimp.
 I have found a assimp-vc140-mt.dll (v3.3.1) which I renamed to 
 assimp.dll

 When running my executable it throws a 
 derelict.util.exception.SharedLibLoadException:

 "Failed to load one or more shared libraries:
         assimp.dll - %1 is not a valid Win32 application.
         Assimp64.dll - The specified module could not be found"

 Any idea what's going on? Are 64bit dlls not supported?


I'm not maintaining the package anymore, but this is an error 
from the system loader and has nothing to do with the binding 
itself. It's the sort of error that usually pops up when trying 
to load a 32-bit DLL into a 64-bit program, or vice versa. Are 
you sure it's a 64-bit DLL?
Sep 28 2021
parent russhy <russhy gmail.com> writes:
On Wednesday, 29 September 2021 at 02:47:09 UTC, Mike Parker 
wrote:

 On Tuesday, 28 September 2021 at 16:30:09 UTC, Eric_DD wrote:

 I am trying to use a newer version of Assimp.
 I have found a assimp-vc140-mt.dll (v3.3.1) which I renamed to 
 assimp.dll

 When running my executable it throws a 
 derelict.util.exception.SharedLibLoadException:

 "Failed to load one or more shared libraries:
         assimp.dll - %1 is not a valid Win32 application.
         Assimp64.dll - The specified module could not be found"

 Any idea what's going on? Are 64bit dlls not supported?


 I'm not maintaining the package anymore, but this is an error 
 from the system loader and has nothing to do with the binding 
 itself. It's the sort of error that usually pops up when trying 
 to load a 32-bit DLL into a 64-bit program, or vice versa. Are 
 you sure it's a 64-bit DLL?



why my messages are not sent?
Sep 29 2021
prev sibling parent Guillaume Piolat <first.name notexisting.com> writes:
On Tuesday, 28 September 2021 at 16:30:09 UTC, Eric_DD wrote:

 I am trying to use a newer version of Assimp.
 I have found a assimp-vc140-mt.dll (v3.3.1) which I renamed to 
 assimp.dll

 When running my executable it throws a 
 derelict.util.exception.SharedLibLoadException:

 "Failed to load one or more shared libraries:
         assimp.dll - %1 is not a valid Win32 application.
         Assimp64.dll - The specified module could not be found"

 Any idea what's going on? Are 64bit dlls not supported?


If using dub you can build your D programs with
   dub -a x86 for a 32-bit executable
   dub -a x86_64 for a 64-bit executable (which is also the 
default thankfully).

Your problem is very probably trying to load a 32-bit DLL into a 
64 host program.
Sep 29 2021