Best Practices: 3ds Max + VRay + Ozone

[Valtiel]

Hey folks. Here’s how I got them to eventually play nice. If you aren’t interested in the preface and supplementary notes please skip down to the first numbered header in bold.

 

Preface

I bought Ozone awhile ago and finally got around to trying to make it work. On paper, it appeared to give the best control and results with expressed compatibility with my other plug-ins, however documentation/conversation on these things has been a bit sparse and Ozone’s pedigree in the primarily stand-alone Vue is valid cause for pause. I finally got around to wrestling with the three, trying to get them to work. It has been a bit of a journey and I started making notes for myself on best practices and pitfalls to be aware of when working with them. Given the lack of conversation out there supporting users exploring this workflow, I want to share it with the community as I don’t feel everyone should slog through the same process just to get a sweet sky.

 

Extra notes and disclaimers

• For those interested, ForestPack Pro appears, so far, to get along well enough with the rest of this group. Can’t see why they wouldn’t but software developed by different people has all sorts of ways of getting tangled under the hood.
  
• “Best Practices” is a term I’m applying lightly here. I haven’t trialed all settings and a lot more testing needs to be done to call any of these recommendations “best” by any measure. They should be a good start though. Please share your own experiences, corrections, or expansions; they are most welcome.
  
• Sorry but I haven’t produced any visual aides or examples yet and may not get around to it. Hopefully I’ve worded things clearly enough for the text to suffice on its own.
  
• Versions: I’ve been using Max Design 2013, VRay 3.4, Ozone 2015, and Forest Pack Pro 5
  

 

 

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1) Global Ambience does not appear to shadow properly:

e-on’s documentation claims it is more sophisticated than standard and will render only slightly slower. In my tests with VRay, however, GA renders noticeably faster than Standard. However, it creates unrealistic “anti-shadows”. Where you would expect to see occlusion shading and soft shadows - where objects rest on the groundplane - it actually gets brighter. This is more pronounced with VRayMtl than Standard. This issue is apparently isolated from the Sunlight peculiarities discussed below. Testing with different ground geometries also suggests it is not due to the VRay Plane issue discussed here. I’m not sure what is causing this but it appears light from the sky will illuminate geometry and create GI bounces of light but will also pass right through opaque materials, effectively multiplying intensity while failing to shadow areas that should be dark.

 

2) VRay Sun + Ozone for Hybrid Daylight systems

If you were to compare exclusive use of the VRay daylight system to the Ozone model, each has a discrete sun/direct and sky/scattered element to them. VRay’s is the sun object and a sky environment map (Assuming you aren’t using an HDRi dome light). Ozone’s is a standard direct light, an atmosphere effect, cloud objects, and some other magic all moderated by the ‘upstream’ plugin style that understandably owes this detachment to its Vue DNA. Early tests got me the fancy skies that probably attracted you to Ozone but the lighting in the scene was off or unusable. Washed out light and AO, and a difficulty getting strong cast shadows are among some of the more common ones. I understand this can be an issue when lighting with HDRI’s on dome light too and a VRay Sun is often helpful in getting your direct light and cast shadows back.

 

The sun created by Ozone is a standard directional light, even with a photometric spectral model, is very weak with a low multiplier. This multiplier can be turned up but in many of my tests, ozone resets it to a low value when you hit the render button. I have otherwise had little luck with Ozone’s internal settings getting the relative intensity to my liking. The result is an absence or weakness in direct illumination and shadows from the apparently bright environmentally mapped sun. I initially found it lighting my scene adequately but with no palpable direct lighting or cast shadows, even with a dramatically low sun and no atmosphere/fog/clouds to scatter the light. I found that using a VRay Sun in conjunction with Ozone’s atmosphere to be a good solution but it took some duct tape and workarounds to make it functional.

 

The short of it is that the best results I have found is to use the VRay sun as your sun object and Ozone as your environment + sky model, matching their positions, colours and intensities in a semi-manual way, detailed below.

 

3) You might have to adjust sun brightness or physical scale to get decent photometric spectral results on reasonable physical camera settings.

Photometric spectral is much brighter than standard spectral. When using VRay exposure controls and cameras, your exposures will have to admit less light than with standard spectral atmospheres. Relative to the Ozone sky, your VRay Sun will be brighter in standard than in photometric, affecting the relative intensity of your direct-light and shadows vs. ambient. Adjusting multipliers or physical scale can rebalance this. I shoot for 0.25-0.5 on the sun lets me keep using realistic physical camera exposure settings.

 

4) VRAySky Environment Map + Ozone work additively.

Don’t use the Sky Map: The VRaySky environment map will work beside Ozone but will not respond to Ozone, which can be expected. While they don’t create errors or crashes, they both act as if they are the sole atmosphere/sky system and will stack light contributions. VRay will want to create a Sky Environment Map whenever you make a VRay Sun (which you will still want to). If you know you want both environment/atmospheres adding light that way, gopher it. Otherwise, I tend to deactivate the environment map so I’m only worrying about one environmental contribution to the scene.

 

5) Make the VRay Sun invisible:

This keeps its direct light contribution to the scene but it seems that even a time/location match produces slight differences in the position of each system’s sun. This can produce two coronas in the background and/or reflection. Even if matched positionally on a clear sky then things should be fine but this might be tricky to do. Moreover, if the Ozone sun is behind atmospheric effects like clouds or fog, your VRay corona will present an unscreened corona and compromise the aesthetic. In said cases, the VRay Sun’s corona may look unrealistically bright. You may also want to dull its brightness as it is not apparently sensitive to these atmospheric obstructions.

 

6) Ozone will (sort-of) track your VRay Sun and match its sun position, but not when used in a 3ds Max daylight system assembly:

I believe this is in the e-on documentation but it is worth bearing mention here. If you create a daylight system and set the sun to VRay type, Ozone will not see it. You have to deactivate it (unless you want two sun objects) and create an independent VRay Sun. If you want to govern the position of it using the daylight system rig, you’ll simply have to align and link it to the deactivated system’s sun head. This would be a nice change in future Ozones versions as it is redundant. The (sort-of) is elucidated below.

 

 

7) Manually set/animate Ozone’s internal sun to match VRay Sun’s.

Know how the VRay Sun object and Sky map adjust their colour/intensity and the effects of atmospheric scattering according to the sun object’s position in the sky? Also, recall how Ozone has a setting to match its sun’s position with the VRAy sun at render time?

 

The Ozone atmosphere and the ambient light in it do not seem to respond to the VRay Sun’s position. Instead, the atmosphere’s contribution appears to refer to the position of the Ozone sun settings in the atmosphere editor even when the Ozone sun is being automatically moved to the VRay sun’s position in the sky at render time. The workaround is pretty simple: set the position of the sun in the atmosphere editor to the same position as the VRay sun so that the Ozone atmosphere is more closely reproducing light at a comparable time of day.

 

If doing a timelapse, your scene will still get brighter and darker throughout due to the VRay Sun’s self-attenuation but the sky’s contribution will remain constant. If your VRay sun is animated via a linked daylight system as detailed above, you will need to keyframe the timelapse again in the Ozone dialog. Make sure you set the same global location (lat/long) too. At this point, the feature where Ozone performs sun-to-sun tracking is made moot; I reckon you could disable it if you wanted.

 

In my first attempt at matching these timelapse animations, for a reason I haven’t been able to figure out yet, Ozone stopped following the set animation even though the preview inside the dialog showed it going through the whole animation properly.

 

8) Adjust Ozone's FG Contribution:

One of the few posts on e-on’s forums that address the washed out light that many users get will advise you to toggle the switch that connects/disconnects Ozone from VRay’s FG solution. I generally want to keep Ozone’s GI contribution on so that its sophisticated phenomena can light the scene so, in addition to using a VRay Sun for direct light, it may help to drop Ozone’s FG contribution multiplier (found near the disconnection toggle) to 0.5 or less. You may still want to do a material override with a VRayDirt material for and AO pass. I still find my scenes, from a variety of e-on’s templates, to be quite blue from said contribution but that colour can be adjusted in your atmosphere settings or in post.

 

9) VRay Plane and Ozone don’t get along well:

If using a VRay infinite plane and a scene where the sun is below the horizon, create a flipped copy that is offset down by a few units. Otherwise the sky will continue to light your object from the bottom when the sun is below the horizon. It seems after doing a render (I’m on Max 2013 Design w- Ozone 2015), Max will fail to identify, select, or even acknowledge in layer browser the existence of a VRay Plane object until the next restart.

 

10) Spectral models do not work with VRay RT

Pretty short point. It’s probably the lighting model. I’ve only experimented with Spectral models but haven’t gotten around to the simpler ones.

 

11) If you’re not gunning for fancy volumetric effects or flying over the clouds, turn your Ozone sky into an HDRI.

This has been discussed in the other thread and I didn’t think about it until reading said thread. Set up an empty scene with a spectral sky and a spherical VRAy Camera. Make a fancy Ozone sky and render it to a radiance or EXR file. You can then bypass the plug-in for most purposes and render it using a standard dome light.

 

Honestly I foresee this being my primary use for Ozone, given the clunkiness of the upstream atmosphere editor vs. the simplicity of the dome light, not to mention the render-time differences. You can create an endless number of skies for re-use in other scenes and save a couple hundred dollars on purchased HDRI’s, not to mention the fact that you can animate daylight and changing cloud patterns to HDR sequences.

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Hope someone finds that useful, I spent a good chunk of 2 days working on it instead of my Master's degree.

 

I welcome your contributions, critiques, and corrections

 

Cheers,

Riley