[Radiance-general] colorpict and materials

[Lars O. Grobe]

Hi Jack,

thank You for the reply.

> 2.	final reflectance set by base material - colorpict is used to 
> modify reflectance set by material, that is normpat image colorpict 
> modifier is used to modify reflectance set by material

I want to do this, I have the material values, the colorpict is just to 
add some visual credibility ;-) But I also want to have the final 
overall (that means the average over the whole surface, like selecting 
an area in ximage vs. a point) color from the base material.

> So steps as follows:
>
> 1.	acquire sample material image by photography, scan....
> 2.	callibrate sample image with macbethcal
> 3.	use callibrated sample image to estimate average color
> 4.	calculate reflectance based on average color values, grey(r,g,b)
> 5.	normpat the callibrated image

So, if I already have the rgb for the base material (which is plastic), 
do I really have to calibrate (macbethcal) the picture map?

Maybe I show you an example:
--
# porphyry red 1: values from ximage and macbethcal'ed pic
void plastic porphyry_red_1
0
0
5 .09 .06 .05 .02 0

# non-calibrated normpat'ed pic
void colorpict sophia_porphyry_red_1_pattern
13 noop noop noop sophia_porphyry_red_1.pic picture.cal tile_u tile_v 
-s .2 -rx 90 -rz 90
0
0

# give alias the modifier as output from dxf2rad
sophia_porphyry_red_1_pattern alias l_porphyry_red_1 porphyry_red_1
--
Will this be correct?

TIA, CU Lars.
--
Lars O. Grobe
grobe at gmx.net