Noisy shadow edges?

Support Materials and Textures
#1

Hi all,

I’m playing with 2.5 alpha 2 and I’m pretty happy with my first try at a metal film reel except for the way the shadows are rendering. I’m probably making some stupid rookie mistake, but heck if I can figure it out. (Click the thumbnail for a larger version.)

http://mattjordan.com/wp-content/uploads/2010/06/film_reel_w_ball-300x168.png

The material is just a blackish color with reflection turned up and I’ve got a basic 3-point light set up: spot key, hemi fill, and a spot rim. Please let me know if you need more info and thanks for any help!

Matt

#2

Try upping the sample rate for whatever lamp is casting the grainy shadow. This will also increase render time, btw, depending on the amount it’s increased.

#3

Thanks for the tip, chipmasque! That definitely helped with the shadow on the front of the reel (the one cast by the sphere). It didn’t seem to affect the oddness on the inner surface of the back half of the reel itself, though. I may just have to live with this part - and, for all I know, light and shadow really behave this way on the interior of a film reel - but if there’s yet another tip, I’d be glad to hear it!

http://mattjordan.com/wp-content/uploads/2010/06/film_reel_w_ball_ao_s5-300x168.png

Thanks again,

Matt

#4

Looks to me like you have a highly reflective surface for your film reel – RayMirror? That could be producing the “marbled” look to the inner surface (note the sphere’s distorted reflection on the facing surface of the reel).

I did a lot of 16mm editing back in the day, and never once encountered a film reel that had a mirror-like reflective surface. Often they were brushed metal, a pretty matte finish. Some had a semi-gloss but not exactly smooth finish, with small scale surface texture like you get with some kinds of industrial finishes. I think if you just remove the RayMirror, you’ll get a better result overall.

#5

Thanks for the additional input. In this case, I want the reflective look (even though it’s unrealistic), so I’d like to figure out how to get that without the distracting marbled look. Luckily, while working through a tutorial on another aspect of Blender, I came across a different “recipe” for this overall look in the tutorial’s blend file and this one doesn’t have the marbled problem when applied to my mesh. I’m studying the differences in the two approaches now to see if I can understand how to do this from scratch on my own.

Thanks again,

Matt