360 by 180 degree IES files don't work. #112201

New Issue

Sarah-Cartwright · 2023-09-10T12:36:57+02:00

Sarah-Cartwright commented

2023-09-10 12:36:57 +02:00

System Information
Operating system: Windows-10-10.0.19042-SP0 64 Bits
Graphics card: NVIDIA GeForce RTX 2060/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 527.37

Blender Version
Broken: version: 3.6.1, branch: blender-v3.6-release, commit date: 2023-07-17 12:50, hash: 8bda729ef4dc
Worked: Never

Short description of error
Blender's IES file processor does not cover the full specification for IES files.

Exact steps for others to reproduce the error
1: In a new scene add a light that uses an external IES file.
2: Add a node to link to a 360 x 180 degree IES file. Two are included in my attachments.

What happens:
Blender renders the IES light as a simple point light.

What should happen:
A full spherical light should be rendered.

Blender does not follow the following stipulation about over 90 degree samples:
The set of vertical angles, listed in increasing order. If the distribution lies completely in the bottom hemisphere, the first and last angles must be 0° and 90°, respectively. If the distribution lies completely in the top hemisphere, the first and last angles must be 90° and 180°, respectively. Otherwise, they must be 0° and 180°, respectively.

Spec:
https://store.ies.org/product/lm-63-19-approved-method-ies-standard-file-format-for-the-electronic-transfer-of-photometric-data-and-related-information/

http://docs.autodesk.com/ACD/2011/ENU/filesAUG/WS73099cc142f48755f058a10f71c104f3-3b1a.htm

**System Information** Operating system: Windows-10-10.0.19042-SP0 64 Bits Graphics card: NVIDIA GeForce RTX 2060/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 527.37 **Blender Version** Broken: version: 3.6.1, branch: blender-v3.6-release, commit date: 2023-07-17 12:50, hash: `8bda729ef4dc` Worked: Never **Short description of error** Blender's IES file processor does not cover the full specification for IES files. **Exact steps for others to reproduce the error** 1: In a new scene add a light that uses an external IES file. 2: Add a node to link to a 360 x 180 degree IES file. Two are included in my attachments. What happens: Blender renders the IES light as a simple point light. What should happen: A full spherical light should be rendered. Blender does not follow the following stipulation about over 90 degree samples: The set of vertical angles, listed in increasing order. If the distribution lies completely in the bottom hemisphere, the first and last angles must be 0° and 90°, respectively. If the distribution lies completely in the top hemisphere, the first and last angles must be 90° and 180°, respectively. Otherwise, they must be 0° and 180°, respectively. Spec: https://store.ies.org/product/lm-63-19-approved-method-ies-standard-file-format-for-the-electronic-transfer-of-photometric-data-and-related-information/ http://docs.autodesk.com/ACD/2011/ENU/filesAUG/WS73099cc142f48755f058a10f71c104f3-3b1a.htm

golfballHighRes.ies

1.7 MiB

blender360IES.jpg

176 KiB

golfballLight.ies

492 KiB

golfball.jpg

219 KiB

Thea360IES.jpg

288 KiB

Sarah-Cartwright added the

labels 2023-09-10 12:36:58 +02:00

Jesse Yurkovich commented

2023-09-11 03:45:28 +02:00

Our IES parsing code detects 2 problems with your files:

The golfballLight.ies file only has 359 horizontal angles defined, not 360 like it says in the file. It leads to our code rejecting the file as invalid.
The golfballHighRes.ies file only has 359 vertical angles defined, not 360 like it says in the file. It leads to our code rejecting the file as invalid.

Addressing those 2 issues leads to the following render in Cycles:

The high-res version looks "off" but it's difficult to tell what's going on since the file is so large.

Our IES parsing code detects 2 problems with your files: - The `golfballLight.ies` file only has 359 horizontal angles defined, not 360 like it says in the file. It leads to our code rejecting the file as invalid. - The `golfballHighRes.ies` file only has 359 vertical angles defined, not 360 like it says in the file. It leads to our code rejecting the file as invalid. Addressing those 2 issues leads to the following render in Cycles: ![image](/attachments/197dd656-4d05-4a54-b9d3-03ba83a96736) The high-res version looks "off" but it's difficult to tell what's going on since the file is so large.

image.png

315 KiB

Pratik Borhade commented

2023-09-11 09:06:51 +02:00

file only has 359 horizontal angles defined, not 360 like it says in the file... addressing those 2 issues leads to the following render in Cycles

@deadpin hi, curious to know how you fixed this file.

The high-res version looks "off" but it's difficult to tell what's going on since the file is so large.

Maybe we can forward the report to cycles devs?

> file only has 359 horizontal angles defined, not 360 like it says in the file... addressing those 2 issues leads to the following render in Cycles @deadpin hi, curious to know how you fixed this file. > The high-res version looks "off" but it's difficult to tell what's going on since the file is so large. Maybe we can forward the report to cycles devs?

Pratik Borhade added

Status

Needs Information from User

and removed

Status

Needs Triage

labels 2023-09-11 09:06:59 +02:00

Jesse Yurkovich commented

2023-09-11 09:24:06 +02:00

Number of vertical angles specified in yellow. Number of horizontal angles specified in blue -- original file had 360 on line 9.

Number of vertical angles specified in yellow. Number of horizontal angles specified in blue -- original file had `360` on line 9. ![image](/attachments/b9a40c1a-47c7-4ebd-8260-9d594ad33ed8)

image.png

19 KiB

Pratik Borhade commented

2023-09-11 13:23:09 +02:00

Thanks @deadpin, worked :D

Pratik Borhade added

Status

Needs Info from Developers

and removed

Status

Needs Information from User

labels 2023-09-13 11:32:42 +02:00