Blenderproc: Render Scenes at a certain frame

[SchmidtiT]

Hello together,

I have created a scene consisting of several cables. I would like to drop the cables into a box, like a Bin Picking process.
I have already assigned the appropriate physical parameters to all cables.
Now I wanted to ask if it is possible to render the scenes only from a certain frame?
I know that after about 100 frames the cables are in the box and don't move much anymore so I would like to render the scene there is that possible?

Thank yo very much for your help!!

[themasterlink]

Hey,

it is possible, but not without changing the code (at least right now). One question I have is why don't you use the physics module? It would allow you to drop the objects, detect when they are dropped and stopped moving anymore and then these final poses are fixed. In that case you don't have to worry about the frame numbers.

Would that help?

For more docu on the physics module look here.

Best regards,
Max

[SchmidtiT]

Very good tip the module I have not had in mind thanks!
I also tried a little with it around but I always get the same error
AttributeError: 'NoneType' object has no attribute 'substeps_per_frame'
Do you have any idea what I can do about it?

I assigned every Object in the Scene a physics property and I use the module as follows:

[...]    
{
      "module": "object.PhysicsPositioning",
      "config": {
        "min_simulation_time": 10,
        "max_simulation_time": 20,
        "check_object_interval": 1,
        "collision_shape": "MESH"
      }
    },
[...]

[themasterlink]

Hey,

can you check if the basic examples works for you?

python run.py examples/basics/physics_positioning/config.yaml examples/basics/physics_positioning/active.obj examples/basics/physics_positioning/passive.obj examples/basics/physics_positioning/output

If that also fails, make sure to remove blender and git checkout the current version 1.12.0 and then try again.

Best regards,
Max

[SchmidtiT]

Hey thanks for the fast reply!

I now downloaded the most recent version but still get the Error message...
Is it a problem, when I assign the physics properties inside of Blender instead of in the config file?
Thats an Idea I came up with because that's the one thing that's different from the example

[themasterlink]

Hey,

have you tried running the basic physics example? So that we know that the physics simulation works in general, then we can focus on the config file error you might have made. Based on what I have seen I can't see one, but maybe there is one.

Is it a problem, when I assign the physics properties inside of Blender instead of in the config file?

No, that shouldn't be an issue. You can add the --debug at the end and you can then see what blender has internally after it ran your pipeline.

Best,
Max

[SchmidtiT]

Yes I tried the physics basic example and it worked fine so I guess the problem really is within my config file or in my Blender file.
I guess I have to do some trial and error to figure out what causes the exact Error.

I will post the solution here when I found something :)

Thank you very much!
Best, Toby!

[themasterlink]

Hey,

you could share your whole config file and your blend file, then we can help you. Else I have no chance of finding out what is going on.

Best,
Max

[SchmidtiT]

Yes I can!
Is there a preferred way to share files privately? (And I have to say that the files and the code etc. may not look very good I'm quite new to programming and I just hard coded everything down the line...)

[themasterlink]

Hey,

That is okay, you can send it to my email, check out my company page: https://rmc.dlr.de/rm/de/staff/maximilian.denninger/

If you changed any of the python src files, please also send to me. Better would be of course if you fork this repository in a private github and send me an invite.

Best regards,
Max

[themasterlink]

Hey,

thanks for providing the files.

I have no clue why, but it seems that the BlendLoader overwrites something, but I can't figure out what.

However, there is an quite easy fix, just add this line:

        bpy.ops.rigidbody.world_add()

Right before this get executed:

https://github.com/DLR-RM/BlenderProc/blob/d15dba7d69c9374779c70766d3500a1c0c6e4745/src/utility/object/PhysicsSimulation.py#L98-L100

I don't know why this only necessary here, but we will investigate this further.

Best,
Max

[SchmidtiT]

Thank you very much for taking a look at my files!
And now the code is running thank you but I experience some weird behaviour.
For some reason it seems like the specifications from the config file are now overwritten (e.g. I had a resolution of 1024x1024 specified and now it is back to the default of 512x512 and I also adjusted thererun.py file in order to save every image in a continuing manner like 0,1,2,3,... but now the Images get overwritten)

Best,
Toby

[themasterlink]

Hey,

you have to set that again, as the camera pose is not loaded from the .blend file:

https://dlr-rm.github.io/BlenderProc/src.camera.CameraInterface.html#src.camera.CameraInterface.CameraInterface

Here, you can see it used: https://dlr-rm.github.io/BlenderProc/examples/advanced/random_backgrounds/README.html

file in order to save every image in a continuing manner like 0,1,2,3,... but now the Images get overwritten)

That seems more like a python problem, if you need help with your python I would ask you to check stackoverflow. They have most questions already covered :) Happy googling.

Best,
Max

[SchmidtiT]

Alright! Thank you very much for your help!

Best,
Toby