pytorch3d/docs/examples/pulsar_basic_unified.py
Christoph Lassner b6be3b95fb Example and test updates.
Summary: This commit performs pulsar example and test refinements. The examples are fully adjusted to adhere to PEP style guide and additional comments are added.

Reviewed By: nikhilaravi

Differential Revision: D24723391

fbshipit-source-id: 6d289006f080140159731e7f3a8c98b582164f1a
2020-11-04 09:54:17 -08:00

88 lines
3.0 KiB
Python
Executable File

#!/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.
"""
import logging
from os import path
import imageio
import torch
# Import `look_at_view_transform` as needed in the suggestion later in the
# example.
from pytorch3d.renderer import PerspectiveCameras # , look_at_view_transform
from pytorch3d.renderer import (
PointsRasterizationSettings,
PointsRasterizer,
PulsarPointsRenderer,
)
from pytorch3d.structures import Pointclouds
LOGGER = logging.getLogger(__name__)
def cli():
"""
Basic example for the pulsar sphere renderer using the PyTorch3D interface.
Writes to `basic-pt3d.png`.
"""
LOGGER.info("Rendering on GPU...")
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]
LOGGER.info("Writing image to `%s`.", path.abspath("basic-pt3d.png"))
imageio.imsave(
"basic-pt3d.png", (image.cpu().detach() * 255.0).to(torch.uint8).numpy()
)
LOGGER.info("Done.")
if __name__ == "__main__":
logging.basicConfig(level=logging.INFO)
cli()