Hello guys,
I was just doing little R&D in my free time i discovered this trick which is so far working well with me. Earlier i used to render AO separately but it is little inconvenient as i need to re-render it every time. Below is my workflow.. let me know if you find it useful too..
Just curious what the softbox is doing to the dirt?
Yeah, I’m kinda curious about that too.
Also curious. Looks like a neat trick.
Given some potential issues with compositing wouldn’t it be best to somehow change the environment background to be white for this AO pass? Not sure if that would be possible though.
such a stupid i am for using softbox.. dont know what i was trying to achieve.. that i land up using softbox.. it should be a simple Vray dirt texture.. 
… ( it is still a new trick for me, i used to render AO separately, dont know if all were already aware & using this technique of rendering AO with extra texture.. 
)
Alpha map should sort this out.. no?
Definitely but out of habit I always render AO passes with a white BG to avoid the potential for a black fringe.
I’d also have a look at turning off consider for anti aliasing in some cases - it can ramp up your render times quite a bit.
Yeah we often throw in a ExtraTex with dirtmap in our elements much like you have done here. I thought it was a pretty standard thing everyone was doing?
There can be a significant render hit when including this element, it is not quite for free.
Nice trick we regularly use for some time, but not the most efficient IMO. I wish we had the same workflow than the one provided by finalRender:
- set AO on in renderer option (and tweak values if needed)
- add AO render element, which provides an option to output AO set up in GI settings (AFAIR, it was called “Output GI details” in finalRender)
→ you’re done !
That’s one of the little things I regret using VRay compared to finalRender (but for many other things, I prefer VRay for sure 
)
Regards.
I turn off GI, turn off camera exposure, and I use a VRayLightMtl for my material override. In the VRayLightMtl, I use a Vray DirtMap.
Yup, that’s another good solution. BUT for us, doing additional passes is not possible, or at least not practical at all: since we generally do between 20 - 30 images (sometimes even more) for a single project, we want to get as many things as possible from a single rendering 
It’s like VRay Toon for example, I’d love to be able to render it separately, as an RE, at the same time as the main rendering …
I only work on one image at a time, so it makes sense to me. Without the GI it renders really fast, and when using an element it can double your render times.
Exactly! so far extratexture trick is working fine for me.. lets see what hurdles i face using same in future..
One image at a time ? lucky you so it makes sense for you, I agree !
So when using the extraTex method do you fill in the background manually to apply the AO in post? because to me it seems like fixing up the map afterwards for it to be useful, takes just as long as submitting a quick override job with your initial render?
Well, the extraTex method is fine for me - all the more that we use PSDManager for output, so the ExtraTex RE layer is already set up.
I’m just somehow nostalgic of a finalRender feature allowing to output AO (in GI tab) and/or Detail Enhancement directly in the AO RE … you just need to check Output GI details (or whatever the name is) option in AO RE to get them separately. Pretty straight forward, isn’t it ? 
I remember asking/seeing a request for the extraTex RE to have a user selected bg colour, ie White so fringing is not an issue.
tht will be awesome!
Why not just swap your occluded and unoccluded colours so you’ve black on black and then no fringe? It’d mean an invert in post but that’s not the worst thing in the world?