pytorch3d/docs/examples/pulsar_basic_unified.py
Christoph Lassner 039e02601d examples and docs.
Summary: This diff updates the documentation and tutorials with information about the new pulsar backend. For more information about the pulsar backend, see the release notes and the paper (https://arxiv.org/abs/2004.07484). For information on how to use the backend, see the point cloud rendering notebook and the examples in the folder docs/examples.

Reviewed By: nikhilaravi

Differential Revision: D24498129

fbshipit-source-id: e312b0169a72b13590df6e4db36bfe6190d742f9
2020-11-03 13:06:35 -08:00

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Python
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#!/usr/bin/env python3
# Copyright (c) Facebook, Inc. and its affiliates. All rights reserved.
"""
This example demonstrates the most trivial use of the pulsar PyTorch3D
interface for sphere renderering. It renders and saves an image with
10 random spheres.
Output: basic-pt3d.png.
"""
from os import path
import imageio
import torch
from pytorch3d.renderer import PerspectiveCameras # , look_at_view_transform
from pytorch3d.renderer import (
PointsRasterizationSettings,
PointsRasterizer,
PulsarPointsRenderer,
)
from pytorch3d.structures import Pointclouds
torch.manual_seed(1)
n_points = 10
width = 1_000
height = 1_000
device = torch.device("cuda")
# Generate sample data.
vert_pos = torch.rand(n_points, 3, dtype=torch.float32, device=device) * 10.0
vert_pos[:, 2] += 25.0
vert_pos[:, :2] -= 5.0
vert_col = torch.rand(n_points, 3, dtype=torch.float32, device=device)
pcl = Pointclouds(points=vert_pos[None, ...], features=vert_col[None, ...])
# Alternatively, you can also use the look_at_view_transform to get R and T:
# R, T = look_at_view_transform(
# dist=30.0, elev=0.0, azim=180.0, at=((0.0, 0.0, 30.0),), up=((0, 1, 0),),
# )
cameras = PerspectiveCameras(
# The focal length must be double the size for PyTorch3D because of the NDC
# coordinates spanning a range of two - and they must be normalized by the
# sensor width (see the pulsar example). This means we need here
# 5.0 * 2.0 / 2.0 to get the equivalent results as in pulsar.
focal_length=(5.0 * 2.0 / 2.0,),
R=torch.eye(3, dtype=torch.float32, device=device)[None, ...],
T=torch.zeros((1, 3), dtype=torch.float32, device=device),
image_size=((width, height),),
device=device,
)
vert_rad = torch.rand(n_points, dtype=torch.float32, device=device)
raster_settings = PointsRasterizationSettings(
image_size=(width, height),
radius=vert_rad,
)
rasterizer = PointsRasterizer(cameras=cameras, raster_settings=raster_settings)
renderer = PulsarPointsRenderer(rasterizer=rasterizer).to(device)
# Render.
image = renderer(
pcl,
gamma=(1.0e-1,), # Renderer blending parameter gamma, in [1., 1e-5].
znear=(1.0,),
zfar=(45.0,),
radius_world=True,
bg_col=torch.ones((3,), dtype=torch.float32, device=device),
)[0]
print("Writing image to `%s`." % (path.abspath("basic-pt3d.png")))
imageio.imsave("basic-pt3d.png", (image.cpu().detach() * 255.0).to(torch.uint8).numpy())