Hello,

I have two set of questions regarding the Direct Daylight Matrix and Direct

Sun Coefficient Matrix calculations in the Five-phase method tutorial (

http://www.radiance-online.org/learning/tutorials/fivephasetutorialfiles/Tutorial-FivePhaseMethod_v2.pdf)

that I would appreciate if you could help me with:

OS: Windows 7 (64-bit)

Radinace: 5.0.a.8

Command Line Environment: Git Bash

1- Direct Daylight Matrix and the all-black model:

the all-black model for Direct Daylight Matrix is generated by the

following command:

Command:

$ xform -m black objects/testroom_Swall.rad objects/testroom.rad

objects/ground.rad \

objects/venetianblind.rad | oconv materials/testroom.mat -

objects/viewmtxsurf.rad \

objects/daymtxsurf.rad skies/sky_white.rad > octs/model_allblack.oct

Description:

The "viewmtxsurf.rad" file which contains the definition for the view

polygons (window glazing pane at the interior side) assigned with a glow

modifier, is exempted from the 'xform' call and it is passed to the 'oconv'

with a hyphen: "- objects/viewmtxsurf.rad"

Questions:

- If Radiance is only going to sample random points within the geometric

outline of the daylight polygons (window glazing pane at the exterior side)

to find the sky patch contributions to the Klems' patches, why are the

"viewmtxsurf.rad" and the "venetianblind.rad" (which are both at the

interior side) even passed to the 'oconv' to be part of the

'model_allblack.oct' file?

- What does the hyphen "-" before 'objcets/viewmtxsurf.rad' do in this

procedure? (I have checked the 'oconv' command description but I could not

understand the given explanation for the hyphen)

2- Direct Sun Coefficient Matrix: Illuminance Calculations Vs. Rendering

In the tutorial, the Example 1 describes the application of five-phase

method for illuminance calculations and the Example 2 describes the method

for renderings (luminance maps). There are obviously, overlaps between the

two examples. With regards to the development of the Direct Sun Coefficient

Matrix for illuminance calculations (Example 1), a 'model_suns.oct' file is

generated as follows:

Command (generating the 'model_suns.oct' file):

$ xform -m black objects/testroom_Swall.rad objects/testroom.rad

objects/ground.rad \

oconv materials/testroom.mat - objects/glazing.rad

objects/venetianblind.rad \

objects/glazing_bsdf.rad skies/suns.rad > octs/model_suns.oct

On the other hand, the Example 2 for renderings uses two separate octree

files to generate the Direct Sun Coefficient Matrix: 'model_suns.oct' and

'model_nosuns.oct'

Command (generating the 'model_nosuns.oct' file):

$ xform -m black objects/testroom_Swall.rad objects/testroom.rad

objects/ground.rad | \

oconv materials/testroom.mat - objects/venetianblind.rad >

octs/model_nosuns.oct

Questions:

- Why is the 'venetianblind.rad' passed to the 'oconv' call in the command

generating 'model_suns.oct' without a hyphen "-", whereas the

'venetianblind.rad' is passed to the 'oconv' call in the command for

generating 'model_nosuns.oct' with a hyphen?

- Why is the 'glazing.rad' (which is an identical polygon definition to

'daymtxsurf.rad' with a glass modifier) is included in the 'model_suns.oct'

file but it is excluded from the 'model_nosuns.oct' file?

- Unlike the 'model_allblack.oct' for Direct Daylight Matrix, why is the

'venetianblind.rad' not assigned a 'black' modifier in the Direct Sun

Coefficient Matrix calculations ?

Thank you in advance for your assistance,

Alireza