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Noise in glass object

Posted: Tue Aug 02, 2016 12:55 pm
by MichaelYpes
I am trying to create a glass object with little light emissions in the middle. The middle part of the glass seems to render great but the edges are very noisy. I have tried both pt and pmc which I have enclosed. The glass index is 1.1. Anyone know what settings to get a good glass render. Rawandrendered does them all the time and that is the effect I am trying to achieve. his is obviously the good one :)
Test pictures
Test pictures

Re: Noise in glass object

Posted: Tue Aug 02, 2016 2:11 pm
by aoktar
it looks weird and don't think that's a noise as usual

Re: Noise in glass object

Posted: Tue Aug 02, 2016 3:23 pm
by MichaelYpes
Do you think then that it might be the geometry of the shape? It is an icosa where I have extruded and then put a cloth over it to give it depth of 10cm (now 2cm in new file) and then hypernurbed it. I can provide source file if that helps?

Re: Noise in glass object

Posted: Tue Aug 02, 2016 3:47 pm
by bepeg4d
Yes, weird :roll:
I have tried to reproduce a similar scene but it cleans fast:
Screen Shot 2016-08-02 at 17.14.49.jpg
SpecularrEmission.zip
(155.69 KiB) Downloaded 161 times
maybe something strange in the environment settings :roll:
ciao beppe

Re: Noise in glass object

Posted: Tue Aug 02, 2016 4:36 pm
by MichaelYpes
Thank you @bepeg4d

Your render looked sweet and was exactly what I was looking for. On close inspection I see that I gave the cloth nurbs a minus value and that is what was giving it the weird look. Changing it to a positive value made the render look more like glass.

On another note I like the model you did to as it was more spherical. Which type of sphere did you use and how many segments to get that look :)

Thanks mate.

Re: Noise in glass object

Posted: Tue Aug 02, 2016 4:44 pm
by bepeg4d
I glad to hear that you have solved :)
your reference image is very inspiring, I have used an hexahedron sphere type with 6 segments ;)
ciao beppe

Re: Noise in glass object

Posted: Tue Aug 02, 2016 6:48 pm
by jeanco
I got a similar problem, as well as high render time.

In time: anyone know why the shadow from the emission plane? I did try area light also, but I thought that emission would emitt both ways.

https://drive.google.com/file/d/0B3ne-5 ... sp=sharing (32s) and the viewport/live render: https://drive.google.com/file/d/0B3ne-5 ... sp=sharing

Thanks

Re: Noise in glass object

Posted: Wed Aug 03, 2016 5:43 am
by MichaelYpes
Thanks for you're help @bepeg4d

Decided to change my model a bit but pleased with the outcome thanks to your help :)
134 Glass Ball 2_0001.png

Re: Noise in glass object

Posted: Wed Aug 03, 2016 5:48 am
by bepeg4d
Great! Well done :)
ciao beppe

Re: Noise in glass object

Posted: Wed Aug 03, 2016 6:01 am
by bepeg4d
jeanco wrote:I got a similar problem, as well as high render time.

In time: anyone know why the shadow from the emission plane? I did try area light also, but I thought that emission would emitt both ways.

https://drive.google.com/file/d/0B3ne-5 ... sp=sharing (32s) and the viewport/live render: https://drive.google.com/file/d/0B3ne-5 ... sp=sharing

Thanks
Hi jeanco,
no, the emission always goes in the polygon normal direction. You have to use at least a cube for having the emission in all the directions, and avoid intersections between emissive polygons and other geometry to avoid noise ;)
ciao beppe