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How to preview a light expert result

This tutorial demonstrates how to review the light expert simulation result.

Prerequisites

Perform imports

from pathlib import Path

from ansys.speos.core import LightPathFinder, Project, Speos, launcher
from ansys.speos.core.simulation import SimulationInteractive

Define constants

The constants help ensure consistency and avoid repetition throughout the example.

HOSTNAME = "localhost"
GRPC_PORT = 50098  # Be sure the Speos GRPC Server has been started on this port.
USE_DOCKER = True  # Set to False if you're running this example locally as a Notebook.
RESULT_NAME = "Direct.1.Irradiance.1.lpf"

Model Setup

Load assets

The assets used to run this example are available in the PySpeos repository on GitHub.

Note: Make sure you have downloaded simulation assets and set assets_data_path to point to the assets folder.

if USE_DOCKER:  # Running on the remote server.
    assets_data_path = Path("/app") / "assets"
else:
    assets_data_path = Path("/path/to/your/download/assets/directory")

Start/Connect to Speos RPC Server

This Python client connects to a server where the Speos engine is running as a service. In this example, the server and client are the same machine. The launch_local_speos_rpc_method can be used to start a local instance of the service.

if USE_DOCKER:
    speos = Speos(host=HOSTNAME, port=GRPC_PORT)
else:
    speos = launcher.launch_local_speos_rpc_server(port=GRPC_PORT)

Create a new project

In this example, a project is created via reading a pre-defined .speos file. It can be found there is volume conflict in this project.

p = Project(
    speos=speos,
    path=str(assets_data_path / "error_data.speos" / "error_data.speos"),
)
p.preview(viz_args={"opacity": 0.7})

/home/runner/work/pyspeos/pyspeos/.venv/lib/python3.10/site-packages/ansys/speos/core/project.py:793: UserWarning: The pySpeos feature : SourceSurface needs a Speos Version of 2025 R2 SP0 or higher.
  src_feat = SourceSurface(
/home/runner/work/pyspeos/pyspeos/.venv/lib/python3.10/site-packages/ansys/speos/core/project.py:850: UserWarning: The pySpeos feature : SimulationDirect needs a Speos Version of 2025 R2 SP0 or higher.
  sim_feat = SimulationDirect(

Retrieve the simulation feature, add light expert and run

sim = p.find("Direct.1")[0]
sim.set_light_expert(True)
sim.commit()
sim.compute_CPU()

/tmp/ipykernel_8493/3328249474.py:2: UserWarning: Please note that setting a value for light expert option forces a sensorcommit when committing the Simulation class
  sim.set_light_expert(True)

[upload_response {
  info {
    uri: "a6736664-a06a-4768-b060-e486691bc069"
    file_name: "Direct.1.Irradiance.1.xmp"
    file_size: 1721902
  }
  upload_duration {
    nanos: 5069346
  }
}
, upload_response {
  info {
    uri: "c4d17073-7a2c-4efe-8358-41932156faa2"
    file_name: "Direct.1.Irradiance.1.lpf"
    file_size: 4690879
  }
  upload_duration {
    nanos: 6343087
  }
}
, upload_response {
  info {
    uri: "87cea39f-db18-4542-878f-ca2814027b51"
    file_name: "Direct.1.html"
    file_size: 276582
  }
  upload_duration {
    nanos: 724915
  }
}
]

If looking to the simulation report, we will find that we have 40% simulation error

import ansys.speos.core.workflow.open_result as orf

# Methods from workflow class provide a way to find the correct result file.
# Detailed information can be found in the workflow_open_result example.
data = orf._find_correct_result(sim, "Direct.1.html")

when reviewing The ray data using LightPathFinder class. We can see a lot of rays missing

path = orf._find_correct_result(sim, RESULT_NAME, download_if_distant=False)
lxp = LightPathFinder(speos, path)
lxp.preview(project=p)

<ansys.speos.core.lxp.LightPathFinder at 0x7f2328358df0>

Create an Interactive simulation with light expert

We will define an interactive simulation to have a look at the rays in error as a direct simulation will only show the rays hitting the sensor not the rays in error.

interactive_sim = p.create_simulation("error", feature_type=SimulationInteractive)
interactive_sim.set_light_expert(True)
interactive_sim.set_sensor_paths(["Irradiance.1:70"])
interactive_sim.set_source_paths(["Surface.1:4830"])
interactive_sim.commit()

<ansys.speos.core.simulation.SimulationInteractive at 0x7f2328359030>

Preview the light expert result

Here, we will run the simulation and preview the result via LightPathFinder class. By default, the LightPathFinder class will preview the first 100 rays stored in the lpf-file.

results = interactive_sim.compute_CPU()
path = orf._find_correct_result(interactive_sim, "error.lpf", download_if_distant=False)
lxp = LightPathFinder(speos, path)
lxp.preview(project=p)

<ansys.speos.core.lxp.LightPathFinder at 0x7f2328359210>

Preview the light expert result with error filter

ray_filter option is provided in the preview function that user can filter the rays to see only rays in error. In this example, error rays are generated due to a volume conflict between two solids.

lxp.filter_error_rays()
lxp.preview(project=p, ray_filter=True)

<ansys.speos.core.lxp.LightPathFinder at 0x7f2328359210>

speos.close()

True