"Isaac Sim 4.5" has many issues with "Non-Visual Materials".The documentation also contains errors (original) (raw)

Isaac Sim Version

4.5.0

Operating System

Ubuntu 22.04

I’m very sorry, but I’ve encountered a series of issues while using Isaac Sim 4.5.

I wanted to use “Non-Visual Materials” to create some “point cloud noise”, so I followed the documentation and ran some tests, but I discovered many problems.

I launched Isaac Sim 4.5 according to the documentation in order to use “Non-Visual Materials”. The startup method was as follows:

./isaac-sim.sh \
--/rtx/materialDb/nonVisualMaterialCSV/enabled=false \
--/app/rtxSensorSample/contentMaterialTest/enabled=true \
--/rtx/rtxsensor/coordinateFrameQuaternion="0.5,-0.5,-0.5,-0.5"

First, the examples in the documentation don’t match what’s actually in Isaac Sim 4.5.

1

I located the sample case by following the specified path, but encountered some issues upon opening it.

When I switched to the “RTXSensorSample” camera, I found it was completely different from what the documentation described.

2

The green materials were just ordinary materials, not as expected.According to the documentation, there should be “custom string inputs: nonvisual:attributes=‘emissive’” configurations for these “Non-Visual Materials.” However, in reality, they are just standard PBR materials. As a result, even after switching cameras, they produce no effect.

3

4

Later, I created a new scene to conduct further testing. The green section was assigned a “Non-Visual Material” by adding it via “Add” + “Attribute,” with the material named “b.” All other materials remained standard PBR materials labeled “a.”

5

Next, I added an “RTXSensor” to the scene.Since I noticed some configuration requirements, I restarted Isaac Sim and set up the necessary parameters before creating the “RTX sensor” in Python.

6

Here’s my complete code implementation:

import carb
carb.settings.get_settings().set_bool("/rtx/materialDb/nonVisualMaterialCSV/enabled", False)

import omni.kit.commands
from pxr import Gf
import omni.replicator.core as rep
lidar_config = "Example_Rotary"

# 1. Create The Camera
_, sensor = omni.kit.commands.execute(
    "IsaacSensorCreateRtxLidar",
    path="/sensor",
    parent=None,
    config=lidar_config,
    translation=(-5.83932, 0, 1.0),
    orientation=Gf.Quatd(1,0,0,0),
)
# 2. Create and Attach a render product to the camera
render_product = rep.create.render_product(sensor.GetPath(), [1, 1])

# 3. Create Annotator to read the data from with annotator.get_data()
annotator = rep.AnnotatorRegistry.get_annotator("RtxSensorCpuIsaacCreateRTXLidarScanBuffer")
annotator.attach(render_product)

# 4. Create a Replicator Writer that "writes" points into the scene for debug viewing
writer = rep.writers.get("RtxLidarDebugDrawPointCloudBuffer")
writer.attach(render_product)

However, the results were disappointing - it appears to have no effect at all. My intended outcome was for the laser to generate some noise when hitting the mirror, but currently there’s no observable effect.

7

I’m unsure where the issue lies. It seems the “Non-Visual Materials” aren’t functioning as expected to achieve the desired simulation behavior.

I’d really appreciate some guidance on this issue.
Collected_111.zip (3.8 KB)

VickNV July 1, 2025, 7:37am 2

Has this issue been resolved? I am unable to reproduce this problem. My observations are consistent with the documentation.

Julie_A July 7, 2025, 1:48am 4

@VickNV I am very sorry, I have tried multiple times and the result is still the same mistake as before.

adiljus2 November 18, 2025, 3:09pm 5

Hello, any solutions to this? I am using Issac Sim 5.1.0 and still not able to simulate “point cloud noise” even after setting the Non-visual materials correctly.

Julie_A November 19, 2025, 9:05am 6

@adiljus2
I’ve been following up on this issue, but I still haven’t managed to retrieve any point cloud data.
Regarding the “RTX Sensor,” how did you create it and obtain the data?

Julie_A November 20, 2025, 2:30am 7

@VickNV @adiljus2

I made the same attempt in Isaac Sim 5.10, setting up “Non-Visual Materials,” but still couldn’t obtain the noise for the point cloud.