Object Scattering - A need for a vRay/Chaos instancer?

[leehenshall]

I know there are plenty of ways to instance objects from within many of the DCC applications vRay is integrated into. But would it be beneficial to have a standardised workflow at a plugin level?

In Maya specifically, I was not particularly impressed with Mash as an instancer and was also disappointed to learn that much of Bi-Frost is not easily integrated with Plugin Nodes (Maybe recent USD integration will help with this?), but last time i checked most of Bi-Frost was completely aimed at using Arnold as the production renderer.

I instead opted to buy vRayScatter plugin from iCube 3D. It was by far the quickest way to get the results i needed. vRayScatter has a nice workflow and helps bring Maya more in line with many superior 3DS Max plugins for scattering/Instancing with vRay assets/proxies. However, it's a very old plugin with its own licence manager & maintenance commitment. I don't really like the idea of buying more licences of this old tool that has been retired in 3DS Max in favour of a new plugin with more features....which isn't available for Maya.

Having used Octane render in C4D. I really liked how there is a scattering tool built into the plugin which also integrates well with the plugins portable/scene file format (ORBX)

I recently created a full environment with a very large amount of scattered objects using vRayScatter plugin. I rendered this on Chaos Cloud but was incredibly frustrated when I came to export vrScene files to upload to Chaos Cloud. It seemed as though it was treating the instances as objects (per frame!!) when creating the portable scene file. This meant that it took a VERY long time to export to chaos cloud.

For a 300 frame shot it ended up generating a 14GB vrscene file which took 2 hours to export. I had over 3000 frames to render, so exporting to Chaos Cloud took a whole day of manaully kicking off these lengthy submissions. This was completely down to the way it was exporting my instances. Due to deadlines I had no time to troubleshoot this. It was also too late to back out of using Chaos Cloud because I had purchased 5000 credits to support this project.

I've tried this same workflow with Mash to see whether it was due to the plugin but it still took a very long time to export. I think the issue stems from vRay Scene Translator not recognising the instanced/scattered objects as instances which makes the files huge. If I had used Maya Batch using a local render farm correctly configured with the necessary plug-ins and licences I could have avoided this issue.

I could be doing something wrong so please do correct me if I'm wrong. But I think if vRay had its own instancer built into the engine it would be able handle these sorts of situations more easily across all host applications.

[SonyBoy]

This is probably OT, but can you elaborate on what it is about MASH that you don't like as an instancer? FYI, so far as I remember MASH simply utilizes Maya's particle instancer anyway, but I've gotten some pretty good results with it for object scattering, in particular by painting. I'm particularly curious as I'm currently gearing up for a project where I'm expecting to have to use such a workflow again.

[leehenshall]

A few factors. The primary being personal preference & workflow. I should probably have said....."I was not particularly impressed with Mash as an instancer for creating 3D environments" things such as placing trees, rocks grass precisely. If you compare it with something like Forest Pack or MultiScatter in 3DS Max. For this kind of work...the workflow is just not as good (in my opinion)

As an instancer Mash does many things including large scale object scattering just fine. Although I personally found that the fine control possible or streamlined environment build workflow in other packages such as Forest Pack was much more difficult to achieve using Mash. I also encountered frequent crashes.

Things like controlling distribution using a bitmap/texture was very easy to achieve using vRayScatter. This was important because my scatter surface did not have many polygons so using a vertex map to control distribution was not a desirable option as i would have needed to add fine subdivsions to get the same control possible with pixels.

I had a 16k satellite image applied to the scatter surface via a vRayMaterial and painted or generated masks in photoshop to tell vRayScatter where to place the trees/grass so that it matched the ariel texture. Doing this in Mash was either not possible or not very easy to find the correct workflow. Whilst trying to research how to control distribution via texture. I encountered unanswered forum posts from other users wanting to do the same. All tutorials that I found during my brief search seemed to only focus on scattering many objects with no masking or using a vertex map to mask not a bitmap.

vRayScatter can easily do other useful stuff like:

• "distance to surface borders" which keeps your scattered objects from getting too close to the edge of your scatter surface.
• Mask by curve/slope/camera frustum
• Patterns
• Each of your scatter object ID's are represented in the viewport by colour as you change the "probability"
• Lots of randomisation control including random colour variation
• Not to mention it is all built into one node with rollouts for all the functions. A lot of mash felt buried in tools which weren't all relevant to environment work.

For my project, paying for vRay scatter was a much a faster option than trying to make Mash work the way I wanted it to. Even though I was paying for a product that is discontinued in Max and mostly unchanged in Maya for many years.

Obviously if Mash works well for others that's great. Just not for me...Also with the improvements to Bi-Frost the only reason to keep mash around is for legacy projects/workflows no? or people like us who aren't using Arnold...

For anyone rendering in Arnold this guy made a nice scattering tool using Bi-Frost scatter nodes:

https://www.envitscript.com/

He even highlights Mash as "buggy" himself as a motivation for making the tool...



As cool as Bi-Frost is.....I still struggle to get on board with the learning curve. Easy "turn key" functionality that scattering tools like vRayScatter/Forest Pack can deliver does just get there much quicker than needing to watch a 2 hour Bi-Frost video to learn how to make a maskable forest. I do appreciate that Bi-Frost is much less linear and has limitless possibilities but as a business sometimes you just need to get something done quickly and easily. Bi-Frost can feel like visual programming at times and does have a sizable learning curve....not to mention it's not exactly vRay friendly so may not even be worth the effort until it is.

This guys tool is basically a wrapper & presets for Bi-Frost to make it work more like the plugins I've mentioned. The problem is....Autodesk are keeping Bi-Frost for Arnold and not allowing crucial functionality required for it play nice with other render engines. Which is why we can't use Env IT with v-ray otherwise I would have purchased this tool. I've also tried things like GraphN but again didn't come close to vRayScatter or ForestPack in real terms and also did not reccogise my vRayProxy as a object it could scatter.

I just think it would be a lot simpler if we could have something made by Chaos that works at a plugin level & plays nice with vRay/Proxies/Chaos Cloud. Similar to how Phoenix makes VFX rendering very easy with vRay.

As things stand unless someone from Chaos can point out something I'm doing wrong...I would not recommend using Chaos Cloud for rendering animated scenes with many scattered/instanced objects. Build some AWS vm's with Deadline instead or use a local farm if you can.

I would however love to have a solution so I can use Chaos Cloud on similar projects in the future. It is the most seamless and easy way to cloud render with vRay with no setup required.

[seandunderdale]

Mash does do some things very very well, but I remember watching a Forest Pack scatter demo on youtube for 3dsMax and its simplicity made me very envious.

[leehenshall]

Mash is great at what it does well and can do a lot of the stuff I liked about C4D. It's a great tool which makes the most of Maya's Non-Bifrost capabilities.

It may interest some that the tool that has replaced vRayScatter in Max "MultiScatter" is in Beta for Maya on request.

I should probably also say that vRayScatter has worked flawlessly for me so don't want to make it sound like it's not worth the money. They are still updating it for latest Maya builds and it does at least still work on Chaos Cloud (but not vantage at least last time i checked). The large VRScene file issue could possibly be resolved without Chaos making their own scatter tool with some support/advice from Chaos Group.

I would still like to put out the idea of maybe having a Chaos tool to rival Forest Pack which could be included in the Chaos Collection. I love Maya and all the new improvements but for me at least and the work I do. It is first and foremost a host for vRay. I choose to use Phoenix instead of Bi-Frost fluids because my workflow is more vRay centric than it is Maya centric. I think a vRay Scattering system that lives in the Chaos Collection makes a lot of sense.

It's also worth mentioning that a basic scatter tool does already exist in vRay for Rhino:

https://docs.chaos.com/display/VRHINO/Scatter

There is a limit to how much we can expect Chaos to make vs integrate with native DCC tools but i think this one is achievable & sensible. Or maybe Chaos can just buy itoo software or MultiScatter

In the meantime vRayScatter does get the job done.

[seq]

We are in the exact same situation: Using VRayScatter for several years now and it always served us well. But with our current project we have suddenly the problem that some of our trees render faulty (e.g. leaves have wrong color and the bark is green tinted). The guy from iCube 3D tried to help, but it did not solve the problem. We still try to find the reason for that very annoying behavior.

And as you wrote: We have the impression that the plugin is not under real development anymore. So we looked around and only found GraphN which looks promising and should be available for V-Ray later that year. But that could easily mean sometimes 2023 or later as they have a lot of aims and the scatter tool is more like a byproduct.

So, yes a great working scatter tool from Chaos would be fantastic! But I guess not very likely.

We also tried MASH, but it gives us not the flexibility and ease of use as VRayScatter. And Bitfrost is surely an amazing technology, but still some way to go, till it is useable for smaller studios without a team of TDs.

[SonyBoy]

MASH of course was originally developed as a motion graphics toolset, then grew into having things like dynamic capabilities so it's very much a Swiss Army Knife. The learning curve for it can be difficult, and for sure there are a lot of workarounds/tricks necessary. And, it does crash a lot. I guess I'm not really sure though why anyone would look to a renderer to have scatter capabilities, which is not a rendering issue at all. If Vray doesn't work with certain scatter/instancing situations, then yes those limitations need to be addressed at the rendering level. But so far as offering a scatter/layout tool itself, this to me would seem to just introduce more potential for conflicts and incompatibilities.

[seandunderdale]

Cosmos isnt a renderer, and neither is Phoenix. Chaos have already branched out into other tools, so perhaps a scatter tool that jives will with Vray and has the best of other tools isnt too much of a wild idea.

[hsz]

Now with BF 2.4 which added support for authoring USD you could use Vray to render directly inside the graph and is fast. So that is another option BF is basically a procedural system so you can change anything at any time without breaking things. And the scattering tools are nice. Yes, it's missing a couple of things but is way more powerful than Mash.
About the SDK so vray can render directly inside the graph (without USD) and add nodes to it. Is coming soon, but then it's up to the chaos developers to integrate, which I hope they do when the time comes.

[oglu]

I agree i see no reason for a instancer if i have Bifrost.
It can do creazy things.

[seq]

Yeah, it can do crazy things for sure. But it is a toolbox not a ready to use tool.

[francomanko]

I used to use Mash also, great tool but totally unreliable, so ended up with the vrayscatter, but this doesnt work as well as it could with vray, not updating in ipr etc so it would be great to have a chaos version.

[hsz]

BF is ready to be used, and it has been used already in production, a few films, and commercials and is being used more and more. So I wouldn't say

it is a toolbox not a ready to use tool.

because isn't accurate

[seq]

You are right: My wording was misleading: Didn't mean that BF is not getting production ready more and more, but that BF provides low level functions which allows you to build up an amazing width scope of higher level tools. But it has e.g. no ready-to-use scatter functions like VRayScatter has. For sure you can build those functions also in BF, but you have to build them first.

The YouTube comment from Jason Brown describes it well:

While Bifrost can technically supplant MASH, it would take a lot of customization to make an interface / workflow to rival MASH. If you want to go through that effort (or are technical enough to just use the Bifrost graph without a MASH-like interface) then yes I would recommend Bifrost since its a faster performing, more extensible system. That said, if you're an artist just looking to play around or quickly build an effect without any ramp-up then MASH is and will be a great tool for a long time to come.

[seq]

Just a note for all VRayScatter user: If there is a VRayToon node in your scene, it could cause problems during rendering (e.g. all scattered objects are red). Thanks a lot to the developers for the bug hunting and the fixing.