Basic - Render a predefined scene¶

To get familiar with ABR, let’s run and render a predefined scene.

At the end of this tutorial you should expect to be able to successfully render a small dataset of images of a metal cap on random backgrounds. It is assumed ABR is already installed and tested, according to our installation

If you are eager to see some images simply jump at the end to see how to commence the rendering. However, if this is your first time using ABR, we suggest you take a look and follow the entire tutotial step by step.

Scene¶

This tutorial is based on a predefined scene located in /src/amira_belender_rendering/scenes/simpleobject.py We suggest to take a look at it and try to understand it. The file can be used as prototypical example in order to set up other scenes. For a more in depth explanation refer to the following tutorial on set up a simple custom sceneario

Assuming you are familiar with python, a few explanations are in order:

the class SimpleObjectConfiguration is used to manage scene specific config values
the class SimpleObject is used to control the logic of the desired scene.

More specifically, at runtime, after setting up a class object, blender calls the generate_dataset which, in turn, takes care of:

randomizing the environment (background) textures
randomizing the pose of the target object (in this case a metal cap)
adjust the file paths through the rendermanager
calling the rendering
performing some post processing steps

def generate_dataset(self):
    # filename setup
    image_count = self.config.dataset.image_count
    if image_count <= 0:
        return False
    format_width = int(ceil(log(image_count, 10)))

    i = 0
    while i < self.config.dataset.image_count:
        # generate render filename: adhere to naming convention
        base_filename = f"s{i:0{format_width}}_v0"

        # randomize environment and object transform
        self.randomize_environment_texture()
        self.randomize_object_transforms()

        # setup render managers' path specification
        self.renderman.setup_pathspec(self.dirinfo, base_filename, self.objs)

        # render the image
        self.renderman.render()

        # try to postprocess. This might fail, in which case we should
        # attempt to re-render the scene with different randomization
        try:
            self.renderman.postprocess(
                self.dirinfo,
                base_filename,
                bpy.context.scene.camera,
                self.objs,
                self.config.camera_info.zeroing,
                postprocess_config=self.config.postprocess)
        except ValueError:
            self.logger.warn("ValueError during post-processing, re-generating image index {i}")
        else:
            i = i + 1

    return True

Data ¶

Make sure the files B.ply and tool_cap_x10.ply are placed in /data/cad/parts. Also, as background textures we use images from Open Images a publicly available large dataset of various images. Make sure to download they images and store them locally, e.g., in a dedicated folder in $HOME/data/OpenImagesV4/Images.

Note: In the tutorial we are going to render images of a metal cap with random background hence, we do not need any other data (such as a dedicated blender scene).

Configuration file¶

Take a look at the configuration file /config/examples/single_object_toolcap_example.cfg. The file is used to specifiy a bunch of configuration values for the dataset we are going to render such as the number of images to render etc.

As you can see, we exploits some enviroment variables in order to parametrize some configuration values and make them agnostic user specific settings. In particular, these are:

OUTDIR: path to folder where the rendered dataset will be stored
DATA: path where backgrounds data are stored
DATA_GFX: path where graphics data are stored

In order to successfully render the dataset, you need to explictly set the above three variables. You can do that e.g., in you ~/.bashrc or inline as shown in the following section.

Commence the rendering ¶

Now all that is left is to submit the rendering. It is assumed you have amira_blender_rendering repo available in your $HOME and that you set up the data as explained above. Then, to commence the rendering run

OUTDIR=~/data \
DATA_GFX=~/amira_blender_rendering/data \
DATA=~/data \
    abrgen --config ~/amira_blender_rendering/config/examples/single_object_toolcap_example.cfg

In case you get

Error: Could not import amira_blender_rendering. Either install it as a package,
or specify a valid path to its location with the --abr-path command line argument.

specify the --abr-path CLI argument as explained here.

Basic - Render a predefined scene¶

Scene¶

Data¶

Configuration file¶

Commence the rendering ¶

Data ¶