Hi,
We just upgraded to vray 3 and i’m struggling with oceantex and hdr reflections. See image below.
with vray sun/sky all is well, but when i put a hdr sky in the background it looks really weird, settings for both renders are the same. There’s so much new ground to cover in vray 3 i was hoping someone had an idea where i should look.
i reset all vray settings with switching to scanline and back and just changed the AA setting from progressive to adaptive sub.
any ideas what could be wrong?
Could you post a thumbnail of the hdr? Is it just that the hdr is very “fussy” with lots of variety and detail compared to the smooth gradient of the vray sky? The ocean tex can generate a lot of very fine detail so you’re almost getting a new normal / direction on the ocean surface per pixel, so each direction is going to pick up a slightly different part of the map it reflects. If you’ve got a really detailed map to reflect it might be very detailed in the reflection element and give you an unpleasing result. I’d be inclined to either reduce the levels of detail in the ocean tex so there’s less small bumps that break the reflections, add in a tiny bit of glossiness to soften the result a bit, or use a simpler looking reflection map.
Thanks for the pointers joconnel, i am indeed using a fuzzy/dramatic hdr, unfortunately there’s no way around that since the client wants a stormy drama sea. I tried a clear blue sky hdr and that could be cleaned up pretty close to a vraysky with AA sampling thresholds. But with the drama hdr the sampling tweaks didn’t help as much.
this is the hdr :
I have a feeling there might be gamma issues too, with vrayhdrmap colorspace inverse gamma 1 instead of srgb, there’s a lot less noise, but then again it might just not be as noticable because of the lower contrast, and ugh, i really don’t want to be mixing up colorspaces.
here is a render with srgb to the left and inverse to the right :
The thing is i can’t remember struggling with this in vray2, the AA sampling seems very different now, maybe i’ll have to do a rollback and check my head.
With the amount of breakup on your sea, I reckon you could quite happily get away with splitting the render with one HDR for reflection, another for the background - you could possibly go with something like a simpler gradient using the same hues and brightness as your hdr, or possibly use a much lower res / convolved version of the original so there’s less variety in there to cause the fuzzy water. I’m doing some ocean text stuff at the minute too and it’s only where something is really close to the water that you can tell that it’s reflecting properly.
I was just cycling in to work and there was a fairly high contrast, detailed cloudy sky over the water. Popped off two photos as reference. The water here is far less stormy than yours - you can see the ripples are way smoother than what you’ve got in your renders (rendering the normals / bump normals would be interesting - see if the different directions are almost per pixel) but the sky is pretty complicated. You get the same fussy look in the reflection as you’re getting unfortunately.
vray oceantex?
where do i find that? 
If you install the phoenix fd demo, it’s a new map type! You can use it permanently without needing a phoenix license, I’m doing that on a current job!
Hi John! thanks a lot! Perfect
great stuff john, thanks! the oceans are really hard to master, never easy to find the right balance between photo realism and what looks pleasing to the eye, references is everything.
it’s so easy to get caught up in the details instead of moving on and seeing the whole picture after post production have killed all the details anyway. still, micro management and details is a good way to understand the tools we are using.
i did a normal render, the directions change per pixel, just enough to cause fuzzy reflections i suppose, so AA sampling will only get you so far. could be a good way to find a oceantex detail/fuzzyness balance.
i will continue my ocean mission with separate background and reflection maps, it would be great to see what you are doing with oceantex, unless it’s confidential
My bits have far simpler skies than yours I reckon, here’s a pretty stormy scene using a simpler hdri - 'Moonfleet' Ship VFX Breakdown
More AA will as you say only get you so far - if there’s a lot of tiny detail, the aa will always resolve at that tiny detail since that’s the correct result for the render, the only thing is it’s not the look you want. Simplify it with a tiny bit of glossiness or pull down your level of detail in the oceantex to soften it out if you wanna stick with the current hdr.
Thanks for posting that clip John. I’ve always wanted to make a stormy ocean like that. Is that all Phoenix?
V Miller
At the time it was a houdini ocean surface being fed through naiad and back into max for rendering, fume and krakatoa stuff. Phoenix has added in new sim things that can be driven by ocean surfaces so it’ll be able to do this very soon and most importantly it’ll keep all the data in one program - we wasted a very large amount of time converting caches between different file formats on that job.
thanks for the information. I’d like to see Phoenix tackle a sequence like that. Keeping everything in one program definitely can be a huge time saver when dealing with multiple simulations.
V Miller
amazing work john, thanks for posting that video and all the tips. i needed some inspiration and got it. i know exactly what to do now, a cheaper version of what i just saw
It’s all on the sim guys and the compositors - I’d very little time to put it out and my renders were disgusting, thankfully a very talented nuke artist called Joe courtis was able to make some nice pictures from the supplied elements
hahah, “disgusting renders”, been there done that. it is beautiful though, when the post work manages to save those shots anyway. i’m really pressed for time as usual, and have no talented nuke guy but myself (- talent), so there will be disgusting in, disgusting out. luckily the client focuses more on the technical aspects of the animation, so i hope it will be ok.
What can help at the expense of a slight amount of render time is a few additional elements.
I tended to render the water with a fresnel map for reflections and play with the curve to have the most change between the flat and peaked parts of the water and the same in the diffuse too going between a deep blue and a greeny blue. You can also render an extra tex with a vray dirt map for your water, invert the normals on it and play with your radius and you’ll get an element that gives you a soft ramp leading up to the sharp crests of the water - you can use this for further CC stuff so you can bring in some fake translucency in the tips of the water or if you colour correct it very harshly, make yourself some pseudo whitecaps. Definitely render out a samplerinfo pass set to UV coordinates too, then in nuke you can use a node called ST map which will take a bitmap or a bit of footage and conform it using the uv render on to the surface of your water with the bitmap or footage sticking to the surface of the water - you can use this to put on foam passes or other noise patterns for variety. Likewise a normal ambient occlusion map for your water so you get a contact shadow for your boat combined with some noise mapped using st map can give you some whitewater around the base of the boat.
wooho! this is golden! thanks a bunch, i really love nuke, but am no compositor so i never get around to learn these sneaky little things. fake translucency and pseudo whitecaps, that last post is a goldmine john. wish the nuke community and forums were as open and helpful as vray’s. alright, i’m definately gonna dig into this, but first, weekend has arrived, my preview has just been shipped and everybody is off for beers, have a great weekend everyone!
Ooh - just for the laugh, get yourself some tileable noise maps or whitewater maps, there’s some on cgtextures, and render them as extra tex elements with the water - a few different scales of the same thing is going to be very useful. You can use the AO element for your whitecap mask, blend it with one of the whitewater bitmap for some detail and have a nice organic looking element.
Thats a good tip! I’ll use that next time I do an ocean for sure.
V Miller
