The Persistence of Vision Raytracer (POV-Ray).
This is the legacy Bug Tracking System for the POV-Ray project. Bugs listed here are being migrated to our github issue tracker. Please refer to that for new reports or updates to existing ones on this system.
FS#246 - Regression on scale limit between 3.7 and previous releases
Opened by Grimbert Jérôme (Le_Forgeron) - Monday, 25 June 2012, 11:50 GMT
Last edited by William F Pokorny (wfpokorny) - Monday, 23 January 2017, 14:09 GMT
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DetailsFrom Thomas de Groot
Using the following code for a (sky) sphere in a scene, with light source well outside the sphere; #version 3.7; global_settings{ assumed_gamma 1.0 } #declare T_sky = texture { pigment { gradient y pigment_map { [0.0 srgb <1.0,0.7,0.6>*1 transmit 0.5] [1.0 srgb <0.8,0.1,0.0>*1 transmit 0.5] } } finish { emission 0.9 diffuse 0.0 } } #declare T_cosmos = texture { pigment { color rgbt <0,0,0,1> } finish { ambient 0.0 diffuse 0.0 } } sphere { <0,0,0>,1 texture {T_sky} interior_texture {T_cosmos} no_shadow no_reflection inverse scale 99.9*10e4 } Working with windows version of POV-Ray and Win7 x64
Is this normal for version 3.7 RC5? I seem to remember that with lower I can indeed confirm that the Ringworld scene does not render correctly anymore, with identical black out. |
Confirmed with Linux 3.7RC6
Seems related to the values in configbackend.h (source/backend/) of SMALL_TOLERANCE & MAX_DISTANCE
Additional comment: unable to duplicate the 3.6.1 reported behavior:
With my 3.6.1 (fresh compilation from source), the picture is also full black for a scale of 100.0*10e4
I will check a 3.5 later.
Well, it's easier to compile 3.1 than 3.5
With 3.1, I got the same behaviour as with 3.6.1 & 3.7RC6 : light red at 99.9*10e4, full black at 100.0*10e4
On 3.1, the difference of render between 99.9*10e4 and 100.0*10e4 is:
Versus (100):
There is no more transmitted ray for the 100.0*10e4
This is for the Unix code. Maybe the Windows distribution used a bigger MAX_DISTANCE (or Max_Distance, it was spelled differently in previous version; but was still 1.0e7 on Unix since 3.1)
POVWIN hasn't used a different MAX_DISTANCE to that in the main source in any build that I can think of, and a look through the old source and revision history seems to confirm that.
For a while (Feb through May 2005) MAX_DISTANCE was 1.0e+10 and SMALL_TOLERANCE 1.0e-6, but apart from that it's had the old values for as long as I can remember.
Now tracked on github as issue #215.