Over Exposed Materials?

[Gavin Lock]

I just had a quick question, and I am sure there is a quick simple answer.  I am trying to make some new concrete materials.  When I make the material it looks good on the sides of a cube or a sphere, however when I switch the preview to a Slab, it is nearly white, when in fact the bitmap is relatively dark grey.  The same happens when I render it (obviously I guess) with the sun on in an exterior rendering.  Am I doing something wrong?  I simply create a new textured material, I think I have tried to change most of the variables, none of which seem to make a difference.  Any ideas?  I have attached the file I am using just in case it would help.

BrushedConc.jpg

 

[Roy Hirshkowitz]

The material looks fine-- it's used unmodified in this image.  It's very likely that nXt's automatic exposure algorithm is overexposing the material when you use it in isolation.  Either add some more objects and materials to the scene, or use the Brightness control to change the overall scene brightness.  Attach an image of the rendering you're getting if you're still having problems.

[Gavin Lock]

Thank Roy, I'll fiddle with it some more.  What is that scene lit with?  Just an HDRI or a sun?  Or both?

[Roy Hirshkowitz]

For comparison, with the Brightness turned down a little:

[Roy Hirshkowitz]

HDRI only.

[Gavin Lock]

Ahhh.  Looks pretty normal when lit with just an HDRI.. gets quite funky when lit with a sun.  Couldn't figure out how to get a darker shadow otherwise.

[Roy Hirshkowitz]

No-- not really.  (The material editor uses HDRI only.)  Here's sun and sky-- brightness turned down slightly:

[Gavin Lock]

What are the setting on your sun for that scene?  Did you simply just turn it on?

[Roy Hirshkowitz]

Yep.  I almost never "set" anything.  The only modification was turning down the brightness a little.

[Gavin Lock]

I am not too sure what I did differently, but I seemed have figured it out somehow.  Out of curiosity, what scale to you put that bitmap to?  Also, are you using pathtracer?  If so how many passes?  My glass seems to get dots in it (4 passes) on the pathtracer, I assume after numerous passes they will go away?

[Roy Hirshkowitz]

This one was actually engine 4, using a standalone version of the product that I'm working on.  Yes, the glass may take a while to resolve (with e4 also).  Bitmap was scaled to 1 meter x 1 meter by default (tiles are 1' x 1').  These renderings were very fast (< 1 minute on my machine.)