How to determine the position of coordinate system origin when use genbox command?

1

Hi everyone,

I recently followed the radiance_tutorial.pdf - Jacobs to use the genbox to generate a simple room. However, I am confused about the coordinate system’s
origin. As shown in the picture, the origin of the room I generated is different from the one in the tutorial. Therefore, I am wondering how to determine the position of the coordinate system origin for genbox command.

a simple room
a simple room1467×602 52.1 KB

Best regards,
Hao

2

Hi Hao,

I think the orientation of the box in the coordinate system is as expected, the view is different. In Axel’s tutorial, the view is from negative x, negative y. In your preview, the camera is at positive x, negative y. In both cases, the box extends 4m along the positive x-, and 5m along the positive y-axis starting at the origin. What is still missing in your scene is the window.

Best, Lars.

2 Likes
3

Hi Lars,

Thanks a lot for your explanation.

Besides, when I use objline | x11meta to preview, do you know how to change the view?

Best regards,
Hao

4

Hi Hao,

objline is a very basic line-drawing program and doesn’t offer different views. It would be nice if it did, but there are plenty of other tools in Radiance for looking at geometry. I recommend trying rvu or “rad -o x11”. It’s worth learning how to use rad early on, as it’s a good introduction to setting Radiance parameters. I don’t remember if it’s introduced in Axel’s tutorial.

Cheers,
-Greg

1 Like
5

Hi Greg,

Thank you for your reply and suggestion. There is one section in Axel’s tutorial to introduce the rad command. I will review that section along with the manpages to learn more about this command.

Cheers,
Hao