pynari - Python Bindings for ANARI

This project provides a python interface for the Khronos ANARI rendering API. This implementation currently requires a CUDA capable GPU (support for other backends will be added at a later time).

Usage - Quickstart

Assuming you already know how the ANARI API works (and that you have pip-installed this package) you can use ANARI in python as follows: First, import this package

import pynari as anari

(for all the steps below we assume you imported pynari as anari; this is not required, but please take this in mind for the examples below).

Once the package has been imported you can then create a ANARI "device" using

device = anari.newDevice('default')

(the 'default' will later allow for selecting between different back-ends, but this current implementation is hard-coded to the 'barney' backend, see https://github.com/ingowald/barney).

You can then create various ANARI actor objects through creator-methods on that device, such as, for example

world = device.newWorld()
mesh  = device.newGeometry('triangle')
array = device.newArray(anari.FLOAT32_VEC3,vertex)

etc.

Large arrays (such as vertex or index arrays for a triangle mesh) are expected to be populated using numpy, and wrapped in the ANARI 'array' type:

import numpy as np
...
vertex = np.array(...,dtype=np.float32)
mesh.setParameter('vertex.position',anari.ARRAY,
                  device.newArray(anari.FLOAT32_VEC3,vertex));
index  = np.array(...,dtype=np.uint32)
mesh.setParameter('primitive.index',anari.ARRAY,
                  device.newArray(anari.UINT32_VEC3,index));

The ANARI API, and how it is exposed in pynari

For a full description of what ANARI Objects are, what kind of objects exist, and how they work, please refer to the ANARI API Spec at https://registry.khronos.org/ANARI/specs/1.0/ANARI-1.0.html .

Since the official ANARI API is a plain C API we could not implement this literally, but had to make certain changes to make ti more "pythonic". Basically, these rules were applied (we will assume that the pynari module was imported under the alias as anari):

• If there is a C constant/enum of name ANARI_XYZ, it is exposed as anari.XYZ. Example: the C enum of ANARI_FLOAT32 is anari.FLOAT32 in pynari.

• If there is a C API function of anariFunctionXyz(ANARIDevice device, ...) it will be exposed as device.functionXyz(...). Note that in order to remain as close to the C-style API as possible we use CAML-case for function names, not python-casing. I.e., pynari uses device.functionXyz(...), not device.function_xyz(...).

Examples

For a list of several samples, please visit the pynari github repo https://github.com/ingowald/pynari

For any issues, please use the github pynari issue tracker.