B249b Wierd glitching at edges of objects with similar coloured material

Is this an anti aliasing issue?
It seems to do it from every angle…
I have a few very similar looking materials (grey polystyrene, grey concrete and stainless steel which is reflecting all that grey!)

Im at a complete loss…

Any help would be greatly appreciated.
Cheers, Matt.


I’ve just rendered this from a different angle and with all materials the same and I am still getting this wierd issue where the AA seems to go crazy around some areas.

I’m pretty desperate to sort this out as I quite close to clicking the big GO button on a 2700 frame animation and I think this is going to occur on every frame where I have these materials…


Cheers, Matt.


Close up of said issue


Some questions & possible things to try:

Are you using a Render Layer compositing? Looks somewhat like alpha-layer issues if so.

Do your materials have the Z-Trans property enabled? If you don’t need it, try disabling it. Z-Trans can cause probs with intersecting meshes, though I’ve not seen it with simple overlaps like this.

If using AO, what settings? Have you tried disabling it to see if it has an effect?

Really shooting in the dark here, haven’t seen anything quite like this before.

Hi Chipmasque.
Just doing a few renders now of raytraced AO (attached images are approx.) and no AO. (I would obviously like AO though.)
None of these renders are through the compositor however renders in this model previously have been. (I dont know whether the fact that they have been at some previous point would in sone way affect any future renders.)
Some object’s materials do have the Z trans turned on (concrete for example) as I have them animated to materialize.
Will check some more settings.
Cheers, Matt.

Its defo the Z trans button in the material. Turned that off on all materials - no glitches.

Only problem is, my concrete object is animated to appear over 2 seconds or so where previously there was nothing!

Not sure what to do…any suggestions?

Cheers! Matt

The problem I’ve seen with ZTrans is usually when one material uses it and another does not – if you need it for your materialization effect, try turning it on for all materials, it might help.

The only other approach I can think of off the top of my pointy li’l head is to use the Compositor and Render Layers to fade in your concrete. A Time node can modulate the Factor of an Alpha Over node to have a Render Layer fade in over another. It’s more complicated, but I’m pretty sure it’ll work without resorting to Material transparency.

Thanks for that, will try the ‘all materials’ option first, if that does’nt work I will go with the compositor solution.
Cheers, Matt.