Bot Raytracing Anomaly

[cmpitts99]

I have found a possible anomaly with bot raytracing. I have replicated this in both Windows and Linux, using versions 7.26.4 and 7.38.2.

I created a simplified .g file with two plate mode bots and two rpps.

bot1.s has 3 points and 1 triangle (0 0 5) (0 5 -5) (0 -5 -5) thickness = 20, centered about hit point
bot2.s has 3 points and 1 triangle (20 0 5) (20 5 -5) (20 -5 -5) thickness = 20, centered about hit point
rpp1.s is from -20 to 20, 5.1 to 25.1, -20 to 20
rpp2.s is from -20 to 20, -25.1 to -5.1, -20 to 20

group1 contains bot1.r
group2 contains bot1.r and bot2.r
group3 contains bot1.r rpp1.r rpp2.r
group4 contains bot1.r bot2.r rpp1.r rpp2.r

When shooting a ray down the negative x axis (-1,0,0), group1 will register a hit down to position -1,0,0
When shooting a ray down the negative x axis (-1,0,0), group2 will register a hit down to position -1,0,0
When shooting a ray down the negative x axis (-1,0,0), group3 will register a hit down to position -2,0,0
When shooting a ray down the negative x axis (-1,0,0), group4 will register a hit down to position -9.99,0,0

I have tested several thicknesses for bot1.s and group4 seem to always register a hit just short of the full bot thickness on the negative side.

[brlcad]

@cmpitts99 Thanks for the report. Can you attach your .g file?

[cmpitts99]

TestBot.g.gz

[starseeker]

I did try to reproduce this but wasn't able to (at least on Linux) - what version of Linux did you see this on?

[cmpitts99]

Rocky 8

[cmpitts99]

I can recreate in mged:
e group1
ae 0 0
nirt -1 0 0 (Hit)
nirt -2 0 0 (Miss)

e group2
ae 0 0
nirt -1 0 0 (Hit)
nirt -2 0 0 (Miss)

e group3
ae 0 0
nirt -1 0 0 (Hit)
nirt -2 0 0 (Hit)
nirt -3 0 0 (Miss)

e group4
ae 0 0
nirt -9 0 0 (Hit)
nirt -9.99 0 0 (Hit)
nirt -10 0 0 (Miss)