Dear all,

rpict with -vh 25.8083 -vv 18.6685 -x 512 -y 512 will create an image of

367x512 pixels.

If I calculate the y dimension by hand, I get:

y/18.6685 = 512/25.8083

-> y = 370.3565132

This number can be rounded up or down to the nearest integer, but how can

it be rounded to 367?

I started doing these hand calculation when I noticed that an image

generated with xwrays|rtrace had a couple of extra lines down the bottom

of it which are outside of the region specified in the view file (for a

parallel view, though).

Cheers

Axel

Hi Axel,

For perspective views, the actual relation for image dimensions involves the tangents of the view angles, not the angles themselves. The relation is:

tan(vh)/tan(vv) = x/y

For more info, see:

http://radsite.lbl.gov/radiance/digests_html/v2n7.html#VIEW_ANGLES

-Greg

## ···

From: "Axel Jacobs" <a.jacobs@londonmet.ac.uk>

Date: March 2, 2005 3:33:36 PM PST

Dear all,

rpict with -vh 25.8083 -vv 18.6685 -x 512 -y 512 will create an image of

367x512 pixels.

If I calculate the y dimension by hand, I get:

y/18.6685 = 512/25.8083

-> y = 370.3565132

This number can be rounded up or down to the nearest integer, but how can

it be rounded to 367?

I started doing these hand calculation when I noticed that an image

generated with xwrays|rtrace had a couple of extra lines down the bottom

of it which are outside of the region specified in the view file (for a

parallel view, though).

Cheers

Axel