Hello,

I am working on a school assignment. I am having problems with "prism2"

while trying to render an interior scene with a prism as a skylight.

I have a room 7.85m x 5.85m, 3.0m in height with a rectangular skylight 2.8mx

2.9m in the centre of the ceiling (I have attached with this email the .rad

file of the prism I made). I am trying to study impact of prism as skylight

on this interior environment, which is meant to be an artist's studio.

Please tell me the correct procedure of using prism2 correctly.

1. The opaque face of the prism faces South while transparent face is

on North. My rendered image with the prism comes out as dark without any

diffused light from North. Why is it so?

2. To get values of A1, A2, A3, A4, I created the geometry in AutoCAD

and measured these values there. Is this a good way of doing this? Or do you

suggest some other way?

3. If I do it correctly, would I be able to see the prism in the

rendered image?

4. Can you send me any sample prism.rad file to understand better?

Please mention the orientation of the prism and its geometry angles.

Here's how I have been doing after editing the .rad files:

- oconv phxsky.rad > phxsky.oct

- mkillum -ab 1 -ad 256 -av 20.7 20.7 20.7 phxsky.oct < mout.rad >

iout.rad

- oconv flr.rad clg.rad wall.rad sill.rad glass.rad prism.rad

phxsky.rad iout.rad > octree1

- rview -vp .1 3 1.7 -vd 7.35 0 0 -vv 78 -vh 90 -ps 1 -ds .05 -ab 1

-ad 256 -av .001 .001 .001 -as 256 -ar 256 -dj .05 octree1

I sincerely appreciate your timely help.

Warm regards,

*Charudatta Joshi (CJ)*

Student, MS-Building Design, ASU

prism.rad (560 Bytes)

Sorry, I have no experience with prism material definitions.

But for a start you should increase the '-ab' value in the rview command.

I assume that the prism material 'consumes' one bounce which means that

you won't see any light reflected off an interior surface. Try '-ab 3'

or more and see if you get a better result.

I hope someone else can help with the prism definition.

Regards,

Thomas

## ···

On 29 Apr 2007, at 20:54, Charudatta Joshi (CJ) wrote:

Here's how I have been doing after editing the .rad files:

oconv phxsky.rad > phxsky.oct

mkillum -ab 1 -ad 256 -av 20.7 20.7 20.7 phxsky.oct < mout.rad > iout.rad

oconv flr.rad clg.rad wall.rad sill.rad glass.rad prism.rad phxsky.rad iout.rad > octree1

rview -vp .1 3 1.7 -vd 7.35 0 0 -vv 78 -vh 90 -ps 1 -ds .05 -ab 1 -ad 256 -av .001 .001 .001 -as 256 -ar 256 -dj .05 octree1

Hi Charudatta,

I'm afraid I can't be of much help, either. I didn't write the fprism routine and I haven't even tested them recently -- can anyone on the list confirm that they are still working in the latest release? I hope so.

Just glancing at your file, the length values seem suspiciously small. Also, your angle of acceptance for source aiming (pi radians) is larger than it should be -- perhaps you put this in there for testing? What is your reference for which lengths correspond to the first four parameters (A1 to A4)? Also, which face is "beta" and which is "gamma?" I'm not certain.

Any help is appreciated. (Raphaël?)

-Greg

## ···

From: "Charudatta Joshi (CJ)" <[email protected]>

Date: April 29, 2007 12:54:32 PM PDT

Hello,

I am working on a school assignment. I am having problems with "prism2" while trying to render an interior scene with a prism as a skylight.

I have a room 7.85m x 5.85m, 3.0m in height with a rectangular skylight 2.8m x 2.9m in the centre of the ceiling (I have attached with this email the .rad file of the prism I made). I am trying to study impact of prism as skylight on this interior environment, which is meant to be an artist's studio. Please tell me the correct procedure of using prism2 correctly.

The opaque face of the prism faces South while transparent face is on North. My rendered image with the prism comes out as dark without any diffused light from North. Why is it so?

To get values of A1, A2, A3, A4, I created the geometry in AutoCAD and measured these values there. Is this a good way of doing this? Or do you suggest some other way?

If I do it correctly, would I be able to see the prism in the rendered image?

Can you send me any sample prism.rad file to understand better? Please mention the orientation of the prism and its geometry angles.

Here's how I have been doing after editing the .rad files:

oconv phxsky.rad > phxsky.oct

mkillum -ab 1 -ad 256 -av 20.7 20.7 20.7 phxsky.oct < mout.rad > iout.rad

oconv flr.rad clg.rad wall.rad sill.rad glass.rad prism.rad phxsky.rad iout.rad > octree1

rview -vp .1 3 1.7 -vd 7.35 0 0 -vv 78 -vh 90 -ps 1 -ds .05 -ab 1 -ad 256 -av .001 .001 .001 -as 256 -ar 256 -dj .05 octree1

I sincerely appreciate your timely help.

Warm regards,

Charudatta Joshi (CJ)

Student, MS-Building Design, ASU

Hello,

I enclose hereafter a JPEG picture which illustrates the dimensions of the prism model you have to define as A1 to A4 parameters (see comments in the fprism.cal file). The picture also shows the naming scheme used for the prism faces (alpha, beta and gamma).

In your scene file, you should decrease parameter A10 to 0.002 (this is the value I always used). And be sure to perform your calculations with parameter -ab set to 1 or more !

Raphael

## ···

________________________________

De : [email protected] [mailto:[email protected]] De la part de Charudatta Joshi (CJ)

Envoyé : dimanche, 29. avril 2007 21:55

À : [email protected]

Objet : [Radiance-general] prism2 problem

Hello,

I am working on a school assignment. I am having problems with "prism2" while trying to render an interior scene with a prism as a skylight.

I have a room 7.85m x 5.85m, 3.0m in height with a rectangular skylight 2.8m x 2.9m in the centre of the ceiling (I have attached with this email the .rad file of the prism I made). I am trying to study impact of prism as skylight on this interior environment, which is meant to be an artist's studio. Please tell me the correct procedure of using prism2 correctly.

1. The opaque face of the prism faces South while transparent face is on North. My rendered image with the prism comes out as dark without any diffused light from North. Why is it so?

2. To get values of A1, A2, A3, A4, I created the geometry in AutoCAD and measured these values there. Is this a good way of doing this? Or do you suggest some other way?

3. If I do it correctly, would I be able to see the prism in the rendered image?

4. Can you send me any sample prism.rad file to understand better? Please mention the orientation of the prism and its geometry angles.

Here's how I have been doing after editing the .rad files:

* oconv phxsky.rad > phxsky.oct

* mkillum -ab 1 -ad 256 -av 20.7 20.7 20.7 phxsky.oct < mout.rad > iout.rad

* oconv flr.rad clg.rad wall.rad sill.rad glass.rad prism.rad phxsky.rad iout.rad > octree1

* rview -vp .1 3 1.7 -vd 7.35 0 0 -vv 78 -vh 90 -ps 1 -ds .05 -ab 1 -ad 256 -av .001 .001 .001 -as 256 -ar 256 -dj .05 octree1

I sincerely appreciate your timely help.

Warm regards,

Charudatta Joshi (CJ)

Student, MS-Building Design, ASU

Sorry my last sentence should have been :

And be sure to perform your calculations with parameter -dr set to 1 or more !

## ···

________________________________

De : [email protected] [mailto:[email protected]] De la part de Compagnon Raphaël

Envoyé : lundi, 30. avril 2007 09:59

À : Radiance general discussion

Objet : RE: [Radiance-general] prism2 problem

Hello,

I enclose hereafter a JPEG picture which illustrates the dimensions of the prism model you have to define as A1 to A4 parameters (see comments in the fprism.cal file). The picture also shows the naming scheme used for the prism faces (alpha, beta and gamma).

In your scene file, you should decrease parameter A10 to 0.002 (this is the value I always used). And be sure to perform your calculations with parameter -ab set to 1 or more !

Raphael

________________________________

De : [email protected] [mailto:[email protected]] De la part de Charudatta Joshi (CJ)

Envoyé : dimanche, 29. avril 2007 21:55

À : [email protected]

Objet : [Radiance-general] prism2 problem

Hello,

I am working on a school assignment. I am having problems with "prism2" while trying to render an interior scene with a prism as a skylight.

I have a room 7.85m x 5.85m, 3.0m in height with a rectangular skylight 2.8m x 2.9m in the centre of the ceiling (I have attached with this email the .rad file of the prism I made). I am trying to study impact of prism as skylight on this interior environment, which is meant to be an artist's studio. Please tell me the correct procedure of using prism2 correctly.

1. The opaque face of the prism faces South while transparent face is on North. My rendered image with the prism comes out as dark without any diffused light from North. Why is it so?

2. To get values of A1, A2, A3, A4, I created the geometry in AutoCAD and measured these values there. Is this a good way of doing this? Or do you suggest some other way?

3. If I do it correctly, would I be able to see the prism in the rendered image?

4. Can you send me any sample prism.rad file to understand better? Please mention the orientation of the prism and its geometry angles.

Here's how I have been doing after editing the .rad files:

* oconv phxsky.rad > phxsky.oct

* mkillum -ab 1 -ad 256 -av 20.7 20.7 20.7 phxsky.oct < mout.rad > iout.rad

* oconv flr.rad clg.rad wall.rad sill.rad glass.rad prism.rad phxsky.rad iout.rad > octree1

* rview -vp .1 3 1.7 -vd 7.35 0 0 -vv 78 -vh 90 -ps 1 -ds .05 -ab 1 -ad 256 -av .001 .001 .001 -as 256 -ar 256 -dj .05 octree1

I sincerely appreciate your timely help.

Warm regards,

Charudatta Joshi (CJ)

Student, MS-Building Design, ASU