noise / black dots

[Jean-Paul Paloux_cg]

Hi,
where does this come from ?


I thought that it was because I don't have enough light... but I have. Do you know why thoses appears ?

Jp
Thx !

[Micha_cg]

noise / black dots

Once a day we all could collect error images and write down the reasons at an user tutorial. I have seen this error befor too. If I remember me right, Joe say's an object without uv coordinates in the scene could cause this. Do you import any mesh object? Ig yes, assign a RCM maooing to it.

An other reason could be, that a HDRI env cause this. If possible, try an other HDRI.

[Jean-Paul Paloux_cg]

noise / black dots

I know, but this one is not a mesh import, it's a simple solid done by extruding a profile curve and some rounding.

The hdri is also the same as I always use, with the same orientation/rotation.

It's the same rectangular lights, it's the same frosted glass material...

I use pretty much the same settings for the quality of the rendering, I used noise threshold of 0.01 and another render at 0.1 and it does the same at the same places...

I think that if I would have to choose it would be an hdri problem more than the others, but it should also get some weird stuff everywhere but it's not the case. it's just here and there on my render windows... no logic behind where it is placed really much...

[joe_b]

noise / black dots

If you'd like you can send me the scene and I can see if anything pops out immediately at me. ftp://ftp.asgvis.com/incoming - let me know the name of the file if you choose to do so.

[Gijs]

noise / black dots

How close is the box to the glass. If I look at the color of the dots, they are green and black as the texture of the cover.
maybe it has to do with sec. ray bias. try to make it 0 or higher than you have.

[Jean-Paul Paloux_cg]

noise / black dots

HI,
it was at 0,
normally I set it at 0.001,
yep they are multiple color on some renders, other times it's only black pixels.

Jp

[Jean-Paul Paloux_cg]

noise / black dots

I just tried it once again at 0 or 0.001 of secondary bias and it still does it...
Jp

[joe_b]

noise / black dots

After playing around with it for a bit I found that disabling maps will remove the "Invalid light cache sample(s)" message. So this brings me back to my initial idea that somehow there is some weird UV stuff going on. I'll mess around with it a bit more, but thats my initial reaction.

[Jean-Paul Paloux_cg]

noise / black dots

initial idea of micha is that it happens that tehre is weird uv going on if we import some meshes from 3ds or something... it's not my case.

Also, there is no maps on this frosted glass... it's juste a vray material applied on a rectangular solid with filletedges and roundings...

This is why it's a little bit weird.

Jp
p.s. I don't do voodoo stuff on my 3d

[Travis Serio_cg]

noise / black dots

I sometimes get the same results when using an environment bmp. I have found that increasing the blur factor makes it go away. However, I can't say that ive seen that much noise on just 1 object. I would think Joe might be on to something there. However, try setting the blur to mip=map and a value higher than .15 and see what happens.

[Jean-Paul Paloux_cg]

noise / black dots

I tried to remove completely the environment map and wihtout any color to the environement also (unchecked). with 0 or 0.001 to secondary bias, still there is this noise.
Jp

[dalomar_cg]

noise / black dots

Ever tried to remodel it. I know its a bad idea, but it seams like you've tried everything else... If it only takes 2-3 min it may be worth it... but then again...

[Gijs]

noise / black dots

Just because the dots appear on the glass, does not necessarily mean that this is the object that causes trouble. One other thing, just to make sure, check if your scene does not have bad objects/inverted normals.

[ALTO]

noise / black dots

Have you checked GI Reflect Caustics? Turn them off!

[merlik585]

noise / black dots

the colors of the dots match the color on the boxes.And the invalid light cache is a mapping problem,something as a mapping with no map assigned.So close the layers on which the boxes are,and see if it makes a difference.And alsoare your maps jpeg? I have had problems with those in vray,i now stick to tga or png.

Renee