[jvanmetre]

Sharing a render from a recently renovated kitchen...1920's center hall colonial...moulding around windows is typical of the era...countertop represents a granite (verde agave) surface...

Noticed the appearance of what I think are caustics -- likely due to large number of surface reflections? SL is about 18.

Hope to improve on the control of the hdr in the background, it looks a little flat.

jvm

[Bubbaloo]

Looks pretty real.
You've definately got a caustics problem.
Are you using real glass in the windows or ags?
Do you have any light fixtures with glass lenses?

[jvanmetre]

Brian-

Thanks for the feedback...really need to add the strawberry jam to the knife and the crumbs from the toast to the countertop to bring it to full reality -- at least for my house.

I just dropped in a lowgradeglass.mxm -- for the windows and glasses, also using a "bulb" form in the lightbulb emitter in three overhead fixtures. Bulbs sit inside a reflective diffuser (it looks like a typical pendant lighting fixture).

jvm

[Bubbaloo]

I wouldn't use low grade glass for the windows, and especially for the light bulbs. Really, unless you can actually see the bulbs in your render, you don't even need them. Just use an emitter plane inside your light fixture. This will speed up your render bigtime and eliminate those caustic spots.

[jvanmetre]

Brian-

Thanks again, agree on using an emitter plane for bulbs not visible. Is there something better than the low grade glass for windows?

jvm

[Bubbaloo]

AGS for windows. It has no render-slowing, caustics-creating refraction, and for windows, this is perfect. You will have to adjust the reflectance to your liking.

[jvanmetre]

Thanks...will give it a go...

jvm

[jvanmetre]

Brian-

I switched the glass to ags...still getting the white dots. I next tried removing the lamp shades covering the overhead lights with no change.

Is it possible to have too many reflective and transparent surfaces?

jvm

[Bubbaloo]

Hmmm...
Are you using hdri for any illumination? Sometimes I get dots when doing that. What are you using for your environment lighting?

[jvanmetre]

Brian,

Yes, I'm using the hdri for illumination...thought I was using it as well for environment lighting?

jvm

[Fernando Tella]

I think your problem might be coming from a way too shiny material. The trouble could be due to a unnaturally shiny layer which have some bump also (which spreads the caustics) and is set to additive mode.

A coating could be causing it too.

Check first the materials near the emitters.

[Tim Ellis]

Could be the old random extra bright pixel in the hdri map.


Open the hdri in HDRShop and equalize it, then resave it.

Tom posted this method in reply to a render with the same spots.

Also using RS:0 (preview engine) can produce these spots too.


What's the material setup for the green cupboards?

eidt:- Also are the downlighters, that can be seen in the window reflection, shining through a glass lens? Remove the lens if so, and that will help.


Tim.