OTOY Forums

Is there any chance that you guys can fix the issue where geo renders invisible or visible with artifacts when you have two faces occupying the same space? Think, adding a label to a bottle, or condensation using displacement with alpha maps. This has been a nagging issue in octane since the beginning. I could be wrong but I feel the like this doesn't exist in Maxwell Render or if it does, the threshold is much much much lower.

Yes, I am aware that you can slightly offset the geo, which in most cases works well enough but when doing condensation on a bottle at high res, which has a label on itthat is already offset, your condensation geo becomes offset so much that you start seeing your condensation floating at the edges.

Setting Ray Epsilon to 0 does not fix this problem as it generally introduces errors elsewhere.

Is there any chance this can be fixed as it's really starting to make Octane a less than ideal choice for work lately.

+1 for that!

why don't you avoid this by very small offset factor?

aoktar wrote:why don't you avoid this by very small offset factor?

That's how I do it now and the small offset becomes noticeable when rendering at very high resolutions, which causes alot of hacks/fixing in post. Especially when a label is on a bottle that also has condensation, the label has to be offset off the bottle then the condensation has to be offset above the bottle AND the label which causes the need for the offset to be even larger.

Forget it if the bottle has a neck foil, a neck wrap label on top of that foil then condensation on top of that, or something similar. Those 3 layers of "small offsets" end up quite noticeable by the time to you get to the condensation.


Here is a full scale wireframe render of section of a bottle i'm working on. This is really the absolute closest I can keep the condensation layer to the bottle without getting that artifact. You can very clearly see the floating drops at the edges.

Theoretically, if Ray Epsilon is set to .0001, as long as my geo is offset .0002 or more, it should be fine, right? if the offset were able to actually be made that small without artifacting, that'd be completely fine with me (although 0 offset would be ideal)--and amount that would be unnoticeable enough. Right now, the closest I can offset it without artifacting is around .006, which as you can see in the image above, is noticeable.

Co planar poly's create artifacts in most software as far as I know. How do you tell the software which poly to render and which to ignore?
What sort of offset are you using?
I run into this issue when rendering lenses/lightpipes on products and normally offset the lens surface by .01mm

Edit.... maybe if we had true single sided polys this could be avoided to some extent?

it's offset .006, which seems very small but at the distance you can very clearly see the floating condensation on the edges when rendered at high res.

see pic a couple posts above.

0.006 inch? If so that's 0.152mm, so quite large. I normally make the offset in a CAD package, so it's pretty easy, but guessing a small offset can be a pain with curved sub D surfaces.

gristle wrote:0.006 inch? If so that's 0.152mm, so quite large. I normally make the offset in a CAD package, so it's pretty easy, but guessing a small offset can be a pain with curved sub D surfaces.

sorry, it's .006 cm.

so the droplets have the top domed surface and a cylindrical back surface, where it is offset from the foil? I guess you wouldn't get the desired effect if there was no back/cylindrical surface?

Completely random thought; is there a way to alter the offset amount based on camera incidence? Are the artifacts more noticable looking normal and less at a glancing angle?