hi
i made a couple of glow balls and render them with pbr in mantra

but the final rendering image has lot of noise .how to improve it?

and why is there an black speckle under the balls?

one more question.
what is the best way to realize such an effect ?
instance light could be considered? I always think that pbr is a good choice

hi

Try increasing the pixel samples in

MANTRA > PROPERTIES > SAMPLING

this will give u good result, but will take some time to render



regards
ranjeet

Try pixel samples between 6 and 12 and increase min ray samples

try getting rid of noise using the micro polygon PBR you need increase the max ray samples , this figure is normally a multiplication of the 2 pixel samples , so if your pixel samples are 12 x 12 you need to increase the max ray samples to 144 which basically 12 squared.

rob

thank you everyone .
thank you circusmonkey.

i increase pixel samples to 32*32 and max ray samples to 1024 then get a clear image.but it take me a long time to render it.

one more question, what is pbr shader ?and how to use it?

Hello all!

According to Peter Bowmar PBR tutorials, Houdini 10 allows you to control the quality of the render through the min and max ray samples oppose to the Pixel Samples. I understand traditionally Micropolygon PBR we needed to mulltiply the Pixel samples to set the Max Ray samples.

Does anyone know how you determine Min and Max ray samples for Houdini 10 PBR?

You can download the scene files from here.
http://www.vimeo.com/6226046 [vimeo.com]

Thanks,

Frank

*NOTE: Peter Bowmar has rightly pointed out that from Houdini 10 you can set your Pixel Samples at a low value (say 3 x 3) and use Min and Max Ray Samples to increase quality for both micropoly PBR and ray-trace PBR. This is much faster than using Pixel Samples of say 10 x 10 as I do here in the video. The project file has been changed to relect this. *