Digital bark and sap: ONYX vs GROWFX


Convincing architectural visualisation, especially if you are aiming at photorealism, requires good vegetation models. Luckily, there is no shortage of high-quality tree and plant models around. These include the Evermotion, Xfrog, Mentor, and iTree collections, just to name a few.

But what if you’re after a very specific, hard-to-find species, or if you want to push the quality of your vegetation one notch higher? A lot can be achieved in generic modelling applications, but a better, faster and more versatile option is to invest into a dedicated plant-modelling solution.

Again, no shortage of options here, including some free ones. In this comparative article, I will focus on two applications that stand out from the crowd: to my left, unvanquished veteran Broadleaf by Onyx Computing, to my right, cocky upstart Exlevel’s GrowFX.

This is not intended as a fully fledged review but as a series of pointers to help readers decide which of these tools best matches their needs.

For the sake of transparency, let me mention that I own licences both of Broadleaf (which I bought) and of GrowFX (which I won at a competition). The developers were not involved in this article and did not provide any test versions. However, I did submit a draft to them ahead of publication and took their comments into account in this text when I felt this was justified. I should also point out that, even though I have a decent command of both apps, I do not consider myself an expert in any of them and am far from having exhausted their capabilities.

Before we get dug in, it has to be said that both Broadleaf and GrowFX are capable of outstanding results in the right hands. Below are two examples of the modeller in action. The Ponce House image includes mostly Broadleaf trees whereas the Graticule House image (the autumn one) was done exclusively with GrowFX trees.

Both are parametric modellers that give users control over the general shape and architecture of their trees but keep these constrained by certain rules. Indeed, on the surface, there is little difference between the models generated in these apps.

One first difference between the two solutions is that Broadleaf is both a standalone application and a 3ds Max plugin whereas GrowFX is a 3ds Max plugin only. So if you’re a C4D, Modo or a Blender person, you’re probably wasting your time reading this.

Another big distinction is that GrowFX was conceived as an all-in-one solution, allowing the creation not just of broadleaf trees but also of evergreens and palms down to individual flowers. Onyx, by contrast, has developed a suite with discrete applications for the creation broadleaf trees, palms, bamboos, conifers, grass and flowers. If you need the ability to model all these different types, you will have to pay $595 for the Garden suite ($695 if you want the 3ds Max plugin) against $325 for GrowFX, making the latter slightly better value. On the other hand, if you only need broadleaf trees or conifers, you can get Broadleaf alone for a mere $195. Onyx also offers various combinations of apps at various prices.

To me, the main strength of Broadleaf lies in its tree library. The app ships with 200 plant setups and their individual textures. Broadleaf lets you model trees from scratch, but most users would start by loading, say, a plane tree and tweaking it until they achieve what they are aiming for. At least that’s how I’ve been using it. The library allows you to generate endless variations of trees fast. Most of the default plants are rather low poly and feel “thin”. But just by upping the leaf density, very realistic results can be achieved.

Onyx Broadleaf in action

The advantage of this huge library is unfortunately offset by what, to me, is Onyx’s most frustrating limitation – its inadequate viewport. Broadleaf hasn’t been substantially updated for a while and it is showing its age. Although it allows the creation of very detailed trees weighing several million polys, it struggles to display them. The trees cannot be rotated live in the viewport but “rebuild” rather slowly if you want to change the POV. Having said that, you can remedy this to an extent by using the spline view, which only shows lines instead of meshes and is a lot more reactive.

Onyx again

Broadleaf’s greatest asset, as it happens, is GrowFX’s Achilles’ heel. The plugin ships completely naked, i.e. with neither library nor preset. New users get thrown in at the deep end and have no other choice but to follow one of the pretty good tutorials on Exlevel’s website in order to create their first tree. Although the tutorials are clear, this can be a frustrating experience as the software’s learning curve is quite steep.


Trees are created by plugging spline paths into one another in a branch network. Each “level” can be precisely controlled with direction modifiers. In addition, almost any of the myriads controls can be influenced by another (for instance, the circumference of a branch can be used to control the length of the twigs or the distribution of the leaves that grow off it). This, for instance, makes it possible for a tree to maintain a realistic shape as it gets bigger or smaller (younger or older), or it can be used to constrain the appearance of blossoms on defined parts of the tree.


Something else only GrowFX has is the ability to instance any piece of geometry on branches and have them behave like leaves or twigs. This makes it easy to adorn your trees with custom made fruit, pine cones, complex flowers or simple buds. In the latest build of the software, these instances can even be scaled.

The application also allows the use of arbitrary geometry to cut into the trees, or te be used as guides for plants to grow around, making hedges and climbers possible. (Onyx has a more basic pruning tool, which allows the cutting of specific branches, something GrowFX doesn’t allow.)

GrowFX’s metamesh option, introduced in the latest version, allows the creation of branches that naturalistically fuse into one another and into the trunk. Metameshes can be painfully slow to compute, but complex networks of roots done that way are a thing of beauty. The branches of Onyx trees, by contrast, are just interpenetrating cylinders, which look fake close up.

GrowFX’s metamesh

Overall, GrowFX provides a lot more controls than Onyx Broadleaf, which leaves more to chance. It is a more refined, more powerful yet also vastly more complex and intimidating solution. Although you don’t need a full command of all the parameters to build decent trees (I have barely scratched the surface myself), you do if you aim to achieve a very specific result. The wealth of controls also makes building a tree a time-consuming affair when Broadleaf allows you to churn out entire forests in a blink. In fact, GrowFX is so complex, with so many windows and parameters, that it is easy to lose the overview over a tree you’ve made. This is the kind of application that would really benefit from a node workflow.

While Broadleaf is a lot more user-friendly, the flipside is that it makes it quite hard to achieve exactly what you want. Instead of giving you full control, Broadleaf lets you influence a tree’s general aspect by nudging some of its characteristics in this or that direction, often via percentage sliders.

As a younger app, GrowFX has a fresher, more modern UI than Onyx’s, although, as a plugin, it is constrained by the limitations of Max, particularly in terms of viewport speed. In Max 2011, orbiting and refreshing a 4m-poly free is neither fun nor fast (it is marginally better in 2012 due to some constraints in displaying very large objects as opposed to large quantities of objects).

I won’t go into details about things both applications do equally well, like generating wind animations or creating both square leaves (for use with opacity maps) and geometry leaves (which in both cases result in heavy meshes that never look very good up close).

GrowFX – Better to use Alpha-mapped leaves

One thing to bear in mind if you create models for a living is that Onyx’s licence does not allow the redistribution of Onyx trees, either as free or as commercial models. I have put a few of my GrowFX creations up for sale here and will continue to do so, but you won’t find any of my numerous Onyx trees for that reason. They can only be used in your own projects.

In lieu of conclusion, I would say that both applications yield very good results. Broadleaf is lot faster but harder to control precisely while GrowFX is more powerful, more accurate, but a lot more time consuming and difficult to learn. Thanks to its metamesh and instance mesh options, the output from GrowFX also enjoys a non-negligible qualitative edge over Broadleaf, especially if your trees are meant to be shown in close-ups.

It is hard to understand why Exlevel decided to ship GrowFX without a library (though the latest version now has the ability to save presets) as this would have given it the upper hand over Broadleaf. I cannot imagine many architecture visualisers investing the time needed to generate decent GrowFX trees, let alone a full library covering a number of species, ages and seasons. As things stand, the two apps will therefore appeal to different audiences without really managing to encroach on their competitor’s constituency.

If you want to generate large quantities of beautiful, botanically plausible trees, don’t care to spend days buried in a manual, and have the money to hand, go for the full Onyx garden suite. If you’re a Max user, want full control over all aspects of your trees, including fruit, flowers and buds, if you want superior meshes with branches merging properly into trunks as well as the ability to sell or exchange your models, go for GrowFX. Either way, you won’t regret your purchase.

36 Responses

  1. 3dwannab says:

    Hi, Have you giving speedtree a go? I’m trying to get it to work with my graphics card (It uses open GL) but no luck. You can download a trial which I’ve not used with it crashing every time I open it. Although it looks amazing. (… If I could get it to work :[ …)

  2. Hans says:

    Hi Bertrand. Good comparison between the parametric tree modelers. As a vray user, I prefer to use tree leaves with no opacity maps. I would prefer to use Growfx in these instances(more options like increased leaf density and blossiming). But for extreme closeups of leaves what would you suggest would be a better option? (detailed leaves with opacities or flat planes with opacities).

  3. Calum Reid says:

    Hi Bertrand. I am on work placement at the moment and have been using 3dsmax for the past few months. I will be graduating next year and will most likely head into this field as my career. But i doubt i will buy max first thing, so i aim to learn blender (free and i prefer the philosophy of open software). You mentioned Arbaro earlier, do you know of any other plug-ins, standalone free software i could use with blender to model trees?

  4. baptiste says:

    Thank you Bertrand for your reply.
    just one other thing, after modeled your trees with grow fx or onyx, how do you scater them? does those plugins have option to do it or do you use vray scater or other? (sorry for the english)

  5. BBB3VIZ says:

    baptiste: No difference. Exlevel is the developer, Itoo a distributor. I do use Forest Pack but it serves a completely different purpose. Forest Pack helps you distribute millions of trees (or anything else) in a scene. You can’t model trees with it, which is what GrowFX, a parametric modeler, does.

  6. baptiste says:

    Hi M. Bertrand. Thank you verry much for this post.
    And what about the itoo software plugin “Forest pack”. did you try it?
    is there a diference betwen exlevel grow fx and itoo software grow fx?

    i’am looking for a good way to make my own vegetation for archiviz scene… itoo , grow fx , Onyx ?

  7. Cariensorry says:

    i hope if you can show me how to model a trimmed bush or transforme any shape to bush

  8. BBB3VIZ says:

    Hi Newt. I do own a Vue licence, but never really took the time to do anything worth mentioning in it. however I would definitely not put it in the same category as the other two. Vue is a full-fledge package, with modelling, animation and rendering tools, which does much more than vegetation. but how the vegetation tools compare with GFX and Onyx I couldnt say.

  9. newt says:

    Hi Bertrand. Thanks for this article. I just had a question. Have you tried e-onsoftware’s Infinite digital environment package? If you have, how does it compare to these two applications? What are its strenghts and weaknesses?

  10. BBB3VIZ says:

    I’m not sure if that’s your question but GrowFX has an option to add random mat IDs to the leaves. You can decide how many additional IDs you’d like to assign and they will get randomly distributed across the canopy.

  11. BBB3VIZ says:

    Hi Mentor. thanks for dropping by. i’ve always considered your trees to be a great demonstration of the power of GrowFX. keep it up! (the roses are superb too).

  12. BBB3VIZ says:

    Yes, Mentor plants are done using GrowFX, though I don’t think there is a formal link between Mentor and Exlevel.
    Having said that, the ability to save presets in the new versions goes some way towards mitigating the lack of libraries.

  13. Psimoh says:

    Really good review. Just want to add that the GrowFX guys have added a new much simplified way to animate wind in their latest beta version: 1.7.0

    Also, I get the impression that the Mentor plants collection is closely associated with the GrowFX software. I could be wrong, but it seems to me that the because the Mentor collection (which I’m guessing was made with GrowFX) is a retail product they don’t want undermine its sales with free/included libraries. Personally I think that’s a mistake as the lack of libraries is the only thing stopping GrowFX being crowned as the superior product.

  14. Ltc says:

    I’m a paid up customer and they refuse to send me a link to download the plugin updates. They refuse to do this probably because they want to force us to spend more money and get the very latest update (for $125). I find this really really dreadful

  15. Ltc says:

    The Onyx interface looks like it was designed in the 1980’s. I hate the look & feel of it. It’s horrible to use in that respect. I also find them quite bad on customer support. In fact on more than one occasion when I have asked for support they have just ignored my emails

  16. Datenland says:

    I’m using Onyx for years now, and I’m a C4d man. ;-) Over the years I only built and rendered the trees alone and put them into the images in postproduction, as neither C4d nor the computers could handle the data. Now with Vray Proxies and the equivalent for the AR-Renderer, I started quite recently to put the trees into the models itself (Archviz) and it really works quite well. I bought one of the collections Bertrand mentioned above and used that as incentive to start using Onyx again. Best way to get them into C4d is via .obj. It even has a C4d-exporter, but the leaves where turned by 180° the last time I tried. Although it’s really lame, the trees are convincing. The only thing I miss is the possibility to shape the trees, be it for a tree that’s growing near a wall or some box-cut crown shape. You might want to look at Katachi’s Dpit Plants, from the demo I had it seems to work similar to GROWFX. (With about the same drawbacks.) It’s completely integrated into C4d.

  17. Hi Bertrandb,

    I allways used Onyx but those joints between trunks and branches is not acceptable anymore imo.

    Easy question. The metamesh option comes for the first time with what GrowFX version? 1.50?

    Cheers and thanks for the cool tuto.

  18. BBB3VIZ says:

    Sorry, I’m no C4D man. I tried it once for about a month and found it utterly puzzling. I started 3D with Blender and used it for a long time. As a Blender user, I found the transition to Max much easier. C4D has a completely different philosophy, I thought.

  19. Scott Dombrowski says:


    3DATS has a site for sharing Onyx trees. It’s been around for a couple of years and there’s not a ton of content on it, but it has potential. It’s sanctioned by Onyx, too… you have to have a valid license to be able to share content.

  20. BBB3VIZ says:

    Hi Chris,
    If you don’t have the time to model in Onyx, then GrowFX is definitely not for you as it is quite a bit slower due to the extra amount of control it gives you.
    As for the .bro files, they cannot be distributed or shared in any way under any circumstances as per the Onyx licence. So, sorry, no Onyx trees from me…

  21. Excellent article Bertrand, I’ve been looking at growfx for quite some time now, and am particularly fascinated by the way it creates the tunk & branches as one object. I’ve been using onyxtree for ages now but never seem to have the time to spend creating amazing high res trees.

    Seeing as you can’t sell the onyxtree trees, would you be so kind as to share the .Bro files for the tree’s you’ve made? Cheeky of me to ask, I know – but if you don’t ask, you don’t get!

  22. BBB3VIZ says:

    Thanks guys.

    Bazooka: The UVs usually need some work in both apps. But GrowFX has its own UV tools in which you can do that. It also makes sense as some people, like me, will be using square maps while others will have rectangular ones. So one size does not fit all.

  23. Bazooka says:

    THis is a great comparison from you bertrand highlighting very critical points,

    I want also to highlight a usual issue in the onyx is that the uvs of every different elements is not symetric in scale wise, u have to always manipulate with the bitmap tilings scale to adjust this and its pretty much annoying actually.

    I dont know how growfx deals with that but it looks as it manage to have the same scale bitmap as the uvs is already welded between different elements

  24. manu says:

    Great review Bertrand, thank you!

    I would love to know more about wind animation capabilities though.

    BTW, that 2d lady (last view) hurts my eyes. ;)

  25. I must admit I found the wind options in onyx a bit weird to get used to. The gust function seemed to give me results as if the tree was being bent over, held and then let go, with it springing back into place a bit unnaturally. The wind option was far more successful though.

  26. BBB3VIZ says:

    Thanks guys.

    Kirya: I did try Arbaro back in my Blender days and remember not being hugely impressed at the time. However, I am looking at their website right now and either it’s made huge progress in the meantime, or its output is much better than I remembered. Might take another look at it now.

  27. Kirya says:

    Thanks, Bertrand! And I want to ask you, didn’t you try the great free tree-generation app Arbaro? What do you think about it?

  28. Aurelalto says:

    Thanks for that great explication Bertrand !! Especially about important thing like trees in a 3d scene ! I will try GrowFX because i just have now my ForestPro license. :)

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