Visibles triangles in render

[fixeighted]

As the attached, I have these dotted line triangles all over my meshes.
I've identified that it's caused by the objects being far away from 0,0,0.
The scene is dimensionally large and the objects need to be where they are in the environment.
Can anyone suggest how I might address this issue please?

[fixeighted]

Panic averted, sort of.
I globally moved everything so that the main hero object is centred, with the hope that the far off displaced terrain
won't show the artifacts as much.

I'd still welcome any other info on how or even if this can be avoided.

[dimitar_panayotov]

Hi! Can you provide more detailed information about your experiment? What is the scale of the object, and how far from the camera is it? What kind of light do you use? Is there any material on the plane? You mentioned something about a displaced terrain. Is it happening on a particular mesh or on all of them if they are at a distance?

[fixeighted]

Hi,

The scene consists of a displaced terrain that is 10km square.
There is a hero object situated off centre by quite a large amount.
The terrain is naturally textured and the hero is simply shaded, with many many tiny
scattered instances on it, which is where I first noticed the triangles appearing.
The camera is generally always viewing the subject rather than the terrain, which acts mainly as a background.
There is just one Vray sun/sky.

The plane image I posted was merely a test object to troubleshoot with, so in that position it had artifacts and after I centred it on 0,0,0,
it was as expected, hence my choice to 'fix' the scene by moving everything so at least my hero object was at 0,0,0

I am still therefore curious as to how we are meant to deal with, for example,
a large environment like this where an object needs to be rendered as travelling from one side to another.
Presumably there would be these errors across a large part of the sequence, until the scene is within some tolerance area where it renders correctly.

[fixeighted]

Here's the simple test scene I used to discover the fault.

[dimitar_panayotov]

Thank you. We are going to look into it.

[fixeighted]

Thanks.
It's not directly affecting the project any more, so no rush.
I cannot detect it occurring in the terrain, so that could be due it not happening when using displacement, or that the shaders
are masking its effects. Either way, I can now render happily and get the job done

[Joelaff]

I have definitely run into lots of issue with Max (and/or VRay) when things are far form the origin. Very annoying, actually, but understandable from a math standpoint. I guess need to use higher precision variables, but that in turn is usually slower. LIke you suggested, moving the objects closer to the original usually solves the problems.

[dimitar_panayotov]

Hi, I wasn't able to reproduce the issue. However, you could try with some small Sec. rays bias values. In some cases, it would help.

[fixeighted]

That's odd.
So you mean you opened that file I linked and it rendered without issue?

I did try altering the SRB but that achieved nothing with any value.

[dimitar_panayotov]

Yes, I rendered the provided scene. Which version of V-Ray did you use to produce the image? Maybe I could try the same one.

[fixeighted]

Latest Vray 6 and Max 23

[fixeighted]

I sussed it out...it happens only when using IPR, which of course I was using extensively whilst
tweaking before final render.
Grrrr....

[dimitar_panayotov]

Yes, it happens on IPR. I was able to eliminate the defect by putting a value of 0,01 on Sec. rays bias.

[fixeighted]

I guess there's a magic value for each case and I missed trying that one...tried others randomly and got no result but good to know, thx.
I was always going to render production so all ended well in any case