Invalid spotlight direction

Hi Radiance experts,
I'm new to radiance and I've came across a problem when using the spotlight
as light source in the scene generation.

In radiance manual I see:
direction (-inf:inf),(-inf:inf),(-inf:inf) Min &
Max infinite
any aimed orientation

Which means I could use any vector as an orientation. But when I tried to
use:
void spotlight lightring3
0
0
7 2000 2000 2000 60 0 1 0
I get a warning: rpict: warning - invalid spotlight direction for ring
"spot2.downlight3"

I'm not sure which part I did wrong. Could I specify a spotlight with
direction 0 1 0?
Best,
Vera

Hi Vera,

I love these sorts of questions, because it means I get to look at code I haven't touched in years...

In this case, I don't think the problem is with your spotlight specification per se. Rather, I believe the vector orientation disagrees with whatever surface you have applied it to. Radiance makes a check to be sure that the spotlight direction is not "behind" the surface you use it with, and this generated an error in your case. Check the geometry you are using with your spotlight, and I think you'll find the problem.

Best,
-Greg

···

From: Vera Liu <[email protected]>
Subject: [Radiance-general] Invalid spotlight direction
Date: June 22, 2014 10:40:16 AM PDT

Hi Radiance experts,
I'm new to radiance and I've came across a problem when using the spotlight as light source in the scene generation.

In radiance manual I see:
direction (-inf:inf),(-inf:inf),(-inf:inf) Min &
Max infinite
any aimed orientation

Which means I could use any vector as an orientation. But when I tried to use:
void spotlight lightring3
0
0
7 2000 2000 2000 60 0 1 0
I get a warning: rpict: warning - invalid spotlight direction for ring "spot2.downlight3"

I'm not sure which part I did wrong. Could I specify a spotlight with direction 0 1 0?
Best,
Vera

Hi Greg,
That was really helpful. I found the problem was because the surface. Thank
you for the prompt reply!

Best,
Vera

···

On Sun, Jun 22, 2014 at 10:58 AM, Greg Ward <[email protected]> wrote:

Hi Vera,

I love these sorts of questions, because it means I get to look at code I
haven't touched in years...

In this case, I don't think the problem is with your spotlight
specification per se. Rather, I believe the vector orientation disagrees
with whatever surface you have applied it to. Radiance makes a check to be
sure that the spotlight direction is not "behind" the surface you use it
with, and this generated an error in your case. Check the geometry you are
using with your spotlight, and I think you'll find the problem.

Best,
-Greg

*From: *Vera Liu <[email protected]>

*Subject: *[Radiance-general] Invalid spotlight direction

*Date: *June 22, 2014 10:40:16 AM PDT

Hi Radiance experts,
I'm new to radiance and I've came across a problem when using the
spotlight as light source in the scene generation.

In radiance manual I see:
direction (-inf:inf),(-inf:inf),(-inf:inf) Min &
Max infinite
any aimed orientation

Which means I could use any vector as an orientation. But when I tried to
use:
void spotlight lightring3
0
0
7 2000 2000 2000 60 0 1 0
I get a warning: rpict: warning - invalid spotlight direction for ring
"spot2.downlight3"

I'm not sure which part I did wrong. Could I specify a spotlight with
direction 0 1 0?
Best,
Vera

_______________________________________________
Radiance-general mailing list
[email protected]
http://www.radiance-online.org/mailman/listinfo/radiance-general