Print at Dec 21, 2025, 6:35:16 AM

Posted by tapia at Jan 15, 2018, 10:53:23 PM
Strange rectangular shadow artifact in rendering
Hi! Firstly I wanted to thank the developers of this software! It is really great! :)

I am using it to model my small apartment and have been having a slightly annoying problem with the render.
I am trying to create a "paper lantern", which is one of those typical balls made of papers that you can hang so you can have a nice light.
So I defined a material, like this:


newmtl lamp
Ns 1.0
Ka 0.3 0.3 0.3
Kd 0.5 0.5 0.5
Ks 0.2 0.2 0.2
Tf 1 1 1
Ni 1.100000
d 0.8
illum 9
sharpness 10

map_Ka lamp_globe_white.png
map_Ks lamp_globe.png
map_Ns lamp_globe.png
map_Kd lamp_globe.png


I am no expert in wavefront, but after playing with the values for a while I think that I got the effect I was looking for:



The problem is that strange artefact (the rectangular shadow) that appears when I make the rendering. If, instead of the defined texture, I apply a color (from within sweethome3d), then I get this result:



There is no artefact anymore. That means that there must be some problem with the definition of my material. But what? Can anybody help me, please?