Squares and lines on rendering particles

[Alessio]

Hi all
I'm working on a jacuzzi simulation but when I run the render I have some problem.
I post the image which is faster to understand.
This is a top view render to check the speed and global result of the simualtion.
Anyone had this kind of problem?
At the moment I tried several resolutions, image sampler subdivs, image filters... some change but nothing solves the problem.
Many thanks for any help.

[Svetlin.Nikolov]

Hey,

First off, which Phoenix and V-Ray versions are you using?

This looks like a Point mode render, am I correct?

Cheers!

[Alessio]

Yes this a point mode render.
Phoenix 31200 max2019

[Paul Oblomov]

I saw those block ages ago, but they were fixed.
Geo mode same ?

[Alessio]

Geo mode same ?

Sorry what do you mean? What setting are you refferring to?
Thanks!

[Paul Oblomov]

Particle shader.

[Alessio]

These are my actual settings. Any advice?

[Svetlin.Nikolov]

Hey, can you send this scene over so we can check it? We need just the simulator, a particle shader, one cache for the frame that causes the issue and the same lighting settings. You can remove everything else is it's sensitive data.

Paul means what if you enable "Render as Geometry".

Cheers!

[Alessio]

Ah ok!!
I did a test and it has the same error.
I will clean the scene to send you the file.

[Svetlin.Nikolov]

Thanks so much!

[georgi.zhekov]

Hey,

This should be fixed in today's nightly build. In order for the shot to render correctly we have introduced a new hidden parameter for the Particle Shader called "ptSizeExtra". By default it's set to 0 and can be increased to suppress such artifacts. You must be very careful because increasing it too much might slow down the rendering a lot.

Select your Particle Shader and from the MaxScript editor set the following code:

$.ptSizeExtra = 0.01

(You will have to find the value that works best for your case, try with small increments like 0.01 or 0.1 first and go up from there)

[Alessio]

Hi thanks for your feedback!
I'm sorry but still had no time to clean the scene and upload it.
Anyway I'll make some test with these settings and will inform you about the results.
Thanks!