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I've never done any 3D modelling, how feasible is it for a programmer to approach it purely via scripting? Im very familiar with Python, and this script doesn't

by dreen 6y ago

I've never done any 3D modelling, how feasible is it for a programmer to approach it purely via scripting? Im very familiar with Python, and this script doesn't look too complex.

Peckingjay 6y ago
Blender has a great Python API[0] that allows you to do almost everything that you could do in the editor with code. You do have to run your code from inside the Blender app though. [0] https://docs.blender.org/api/current/info_quickstart.html https://docs.blender.org/api/current/info_quickstart.html
- jedimastert 6y ago
  I feel like headless blender could be kind of interesting...maybe someone should start a bug? Edit: good thing I searched the bug tracker. Next step, Selenium for Blender!
- capableweb 6y ago
  I'm unsure of why you say "almost" everything when the UI code is simply calling the python API to do it's function. You could do anything and _more_ in the python API, as it's what the UI uses but you can use all the parameters via the code while the UI doesn't expose everything. Unless something changed recently regarding this. Also, regarding executing the code from outside, you can run blender headlessly, running the code with it when running blender via terminal. So you could use it as a windowless client if you so wish.
  - blincoln 6y ago
    Blender is a truly fantastic tool, but some of the scripting is a bit hacky, IMO. I recently built some pretty complex Blender automation[1], and my experience was that while technically nearly everything that can be done in the UI can be automated, there are problems that fell into two main buckets for me: 1 - There are basically two parts to the Python API - bpy.ops, and everything else. If something is in the "everything else" category, it works pretty well, but not everything can be done through that part of the API. bpy.ops is (AFAICT) the equivalent of using Selenium to automate clicking on web pages instead of actually interacting with the underlying API, and it feels super fragile. 2 - A lot of the API is not documented well, and I frequently ran into situations where there was no information on what I wanted to do, or the information was outdated. The impression I get is that most of the core Blender devs and users are not using the scripting features, or not using them extensively, because answers on StackOverflow and similar to things like "how can I change property X of every material's shader in my project, oh, and by the way, I have 1000 materials in my project" are usually "I guess you'll just have to click through each of those and set it" even though the API supports it if one digs far enough. A lot of the extensions I thought I could use as reference for things like arranging shader nodes in a useful way have been broken ever since 2.8, but there's no indication in the UI of this. The pane in the scripting view that continuously shows the script equivalent of actions taken in the UI is a big help, and again, Blender is a really, really fantastic tool. But I can definitely understand some frustration with the scripting feature. [1] https://www.thelostworlds.net/Software/Soul_Reaver_to_Blender_Conversion_Toolchain.html https://www.thelostworlds.net/Software/Soul_Reaver_to_Blende... - better docs are coming soon, I promise.
aidos 6y ago
It’s pretty easy to follow. I’ve been learning Blender over the last month but not delved too deeply into the Python api yet. That source code is really straightforward though. There are 2 parts, the bootstrapping where you tell Blender how to add your tool to the interface, and then the generation code that builds the mesh etc. More complex is understanding the Blender model. Best thing to do is go through something like Blender Gurus donut tutorial. It’s intimidating to start with, but once you know the model you can find your way around and then you start getting into more of the techniques. As a bonus, it has a vim-like interface. So you can do “r x 90” To rotate the selected object 90 degrees about the x axis.

by dreen 6y ago

I've never done any 3D modelling, how feasible is it for a programmer to approach it purely via scripting? Im very familiar with Python, and this script doesn't look too complex.

Peckingjay 6y ago

Blender has a great Python API[0] that allows you to do almost everything that you could do in the editor with code. You do have to run your code from inside the Blender app though. [0] https://docs.blender.org/api/current/info_quickstart.html https://docs.blender.org/api/current/info_quickstart.html

jedimastert 6y ago
I feel like headless blender could be kind of interesting...maybe someone should start a bug? Edit: good thing I searched the bug tracker. Next step, Selenium for Blender!
capableweb 6y ago
I'm unsure of why you say "almost" everything when the UI code is simply calling the python API to do it's function. You could do anything and _more_ in the python API, as it's what the UI uses but you can use all the parameters via the code while the UI doesn't expose everything. Unless something changed recently regarding this. Also, regarding executing the code from outside, you can run blender headlessly, running the code with it when running blender via terminal. So you could use it as a windowless client if you so wish.
- blincoln 6y ago
  Blender is a truly fantastic tool, but some of the scripting is a bit hacky, IMO. I recently built some pretty complex Blender automation[1], and my experience was that while technically nearly everything that can be done in the UI can be automated, there are problems that fell into two main buckets for me: 1 - There are basically two parts to the Python API - bpy.ops, and everything else. If something is in the "everything else" category, it works pretty well, but not everything can be done through that part of the API. bpy.ops is (AFAICT) the equivalent of using Selenium to automate clicking on web pages instead of actually interacting with the underlying API, and it feels super fragile. 2 - A lot of the API is not documented well, and I frequently ran into situations where there was no information on what I wanted to do, or the information was outdated. The impression I get is that most of the core Blender devs and users are not using the scripting features, or not using them extensively, because answers on StackOverflow and similar to things like "how can I change property X of every material's shader in my project, oh, and by the way, I have 1000 materials in my project" are usually "I guess you'll just have to click through each of those and set it" even though the API supports it if one digs far enough. A lot of the extensions I thought I could use as reference for things like arranging shader nodes in a useful way have been broken ever since 2.8, but there's no indication in the UI of this. The pane in the scripting view that continuously shows the script equivalent of actions taken in the UI is a big help, and again, Blender is a really, really fantastic tool. But I can definitely understand some frustration with the scripting feature. [1] https://www.thelostworlds.net/Software/Soul_Reaver_to_Blender_Conversion_Toolchain.html https://www.thelostworlds.net/Software/Soul_Reaver_to_Blende... - better docs are coming soon, I promise.

aidos 6y ago

It’s pretty easy to follow. I’ve been learning Blender over the last month but not delved too deeply into the Python api yet. That source code is really straightforward though. There are 2 parts, the bootstrapping where you tell Blender how to add your tool to the interface, and then the generation code that builds the mesh etc. More complex is understanding the Blender model. Best thing to do is go through something like Blender Gurus donut tutorial. It’s intimidating to start with, but once you know the model you can find your way around and then you start getting into more of the techniques. As a bonus, it has a vim-like interface. So you can do “r x 90” To rotate the selected object 90 degrees about the x axis.