Westkaai via FStorm

Westkaai

Recently, I was given the chance to try out FStorm, a GPU-only renderer being developed by Andrey Kozlov. I’d been intrigued by FStorm since seeing the work of Johannes Lindqvist and Daniel Reuterswärd, two of my favorite Archviz artists, who use it as their main renderer. After a few weeks of experimenting, I wanted to report some initial thoughts.

FStorm has a decent scene converter for Octane, V-Ray and Corona files, so my first step was to convert two V-Ray scenes, which turned out relatively nice with just a few manual tweaks (mainly for SSS materials):

But I also wanted to build an FStorm scene from scratch in order to explore the material workflow. For this, I picked a relatively simple setting: A minimalist interior by Hans Verstuyft Architects in a David Chipperfield tower in Antwerp. All the images below were tone-mapped in the FStorm real-time frame buffer and saved as .jpg, with no further post-production. Scroll down for a summary of my thoughts regarding FStorm.

Westkaai

Westkaai

Westkaai

Westkaai

Westkaai

Westkaai

Westkaai

Westkaai

Westkaai

Westkaai

Clearly, I’ve only scratched the surface of FStorm but here are a few initial thoughts based on this small project.

  • I initially found FStorm to be slow for a GPU renderer when rendering interiors, but this was before I placed portals in my windows. This sped things up considerably. It’s been years since I had to work with portals in any renderer, so it felt strange to go back to them. But why not. They certainly work well here.
  • Bearing this in mind, FStorm in very fast. I won’t make a direct comparison with V-Ray RT or Octane, but it always feels fluid, even on relatively large scenes. It’s particularly good at resolving DOF and bokehs quickly, which can take a long time in other renderers.
  • FStorm has simple but effective tonemapping tools that pretty much remove the need for external post-production on stills. All images here were saved as .jpg from the frame buffer.
  • Compared with V-Ray RT, I missed a good denoising tool, which is sometimes needed to take an almost-clean render over the finish line.
  • I liked the fact that FStorm has essentially one material to cover pretty much all physical properties of real-life surfaces. This is a clear advantage over Octane, whose glossy material doesn’t have SSS and where glossy refraction and glossy reflection can’t be separated.
  • I struggled to wrap my head around FStorm’s SSS settings, though the real-time feedback made it very easy to iterate.
  • One big limitation of FStorm is that it supports none of 3ds Max’s built-in maps and offers only a small set of its own maps, some of which are pretty limited. Its falloff map, for instance, doesn’t allow users to draw a custom curve, which can be frustrating.
  • I painfully missed a triplanar map. It hasn’t been too long since triplanar maps were introduced in V-Ray and Max, but it’s incredible how quickly I’ve come to find them completely indispensable.
  • I found FStorm’s support for normal maps limited and frustrating. Essentially, I haven’t been able to make any asset using normal maps look good. The surface always looked weird. The FStorm bitmap is also missing some important functionalities when used as a normal map loader, such as the ability to flip green and red values (necessary for ZBrush-produced normal maps). For me, this was one of the most limiting aspects of FStorm given my high reliance on normal maps when using photoscanned assets or maps. Traditional bump maps work as expected.

Altogether, I found FStorm very pleasant to use. It gave me very fast feedback on this interior (perhaps the fastest of all real-time renderers I’ve tried so far) and I could generate final 2K images in about an hour each on a single 1080ti.

One caveat to bear in mind is that FStorm is a rental-only application and doesn’t offer permanent licenses. This may or may not bother you, depending where you stand in that debate. Regular readers of this blog know where I stand. I will just say the business model is the main reason why I didn’t look into FStorm earlier, and it will remain a big barrier for many potential users who, like me, would have taken the plunge much earlier had the option of a permanent license been available.

 

    • umut
    • October 23, 2017

    I would like to try to use bump maps to create falloff effects on surfaces,

  1. Corona also recomends to use CoronaPortal material and put it as a plane on windows for faster and less noisy results. Doesn’t it ??

  2. They do based on the size of the openings.

    • PengPeng
    • October 23, 2017

    Will the scene be available for purchase?

  3. @Ronen, that’s true, though with Corona, I never felt I needed them.

  4. @PengPeng, not planning to put it up for sale so far.

    • Johan
    • October 23, 2017

    Looking great. Best thing for me is the carpets tassels.. Standard 3ds max hair & fur? Also did you use Dabarti Capture for the depth/Normal map?

  5. I modeled the tassels with splines and did a few variations of them. I distributed them with RailClone. I used Forrest Pack for both carpets. No Dabarti Capture here. I didn’t find FStorm to handle normal maps well.

  6. Great review. After the spree of stunning visuals of Johannes and Daniel they had me almost convinced to switch sides. I was planning to try Fstorm but needed a extra push. With your review on this and the pro’s and cons I think I wait until they add tri planar and normal support. They are to important for me.

    Great job as usually!

    • Yazan samsam
    • October 24, 2017

    Beautiful work no matter render engine you use, please can I ask you how to get those realistic wood maps, and how did you manage the background in this scene?. And are we going to have more modern spaces by you? Best regards

    • Max
    • October 24, 2017

    Last time I checked it’s not possible to even purchase FStorm at all?

  7. Do you always have to do the best? You are my idol.

    • Juang3d
    • October 24, 2017

    Wow… 2K in 1 hour with a 1080Ti, I find pretty SLOW, it´s a lot for a GPU render engine… I usually got 45 minutes to 1 hour in interiors with Corona in CPU.

    Have you tried other engines to compare times?

    • Matt
    • October 24, 2017

    Hi Bertrand, looks awesome! You should try Redshift. Most limitations you mention doesn’t exist (pretty close to VRay in fact) and it’s by far the fastest engine i’ve ever used!

  8. Hey Matt. Thanks for the input. I definitely want to look into it. I guess I haven’t yet seen a redshift image that really blew my mind, but if it’s fast, it sounds like something I should try, and I’ve heard a lot of good things about it.

  9. @Juang3D: You probably have supercomputer (or you’re working with very simple scenes). I consider 5 to 6 hours for a Corona or V-Ray 2K interior render very fast.

  10. @Yazan. The wood map was just a photograph I took of a discarded piece of furniture on the street. It was then heavily processed in PShop and processed again in Max. The background is a panorama image mapped onto a large cylinder around the scene. It has an alpha that cuts out the sky, so that the sky part of the background is actually coming from the HDR map.

    • Kosta Hantov
    • October 25, 2017

    Exceptional images once again! And a truly professional review thank you for it now I know that I need to wait for the normal map issue to be fixed, since I’m getting into the photogrammetry workflow /again, inspired by you/. I couldn’t figure out tho, what’s the issue with rental licenses from your point of view, it seems I’ve missed that part throughout your blog posts.

  11. Thanks a lot for your reply, wish one day you post such like these tips at your blog, like how to prepare an alpha from a background and how to really manage the photo/texture inside PS even how to texture large surfaces. this is the most accurate wood I ever saw in CGI is there any balance phase related to HDRI?!

    Thanks Again

    • Marinus
    • November 1, 2017

    Hi Bertrand, very nice as always! It is very nice to see the (in)differences between render engines. That made me wonder: do you think the software that is used (So e.g. Max, C4D, Blender) has any influence on the outcome of the used renderer? I’m using both Max and C4D but I find it much harder to get a satisfying image out of C4D using Vray. I can’t really put my finger on it why that is, it’s just a gut feeling. I know you’ve been using Blender in the past, was this one of the reasons why you’ve switched to Max?

  12. I’ve had some success with FStorm and have found it to be rapid compared to VrayRT and others. The direct kernel feature is fantastic. It limits multi bounces to a radius that you set. There is a trade off between time and light bounce in corners but it worked well for me.
    I was getting render times of 40 minutes @4k on two GTX980’s.
    Very happy

    • RimasV
    • November 9, 2017

    The great thing about FStorm is that you can slot more GPUs into your system and make renders F.A.S.T. Can’t do that with CPU renderers, need extra nodes or very specialized and expensive motherboards with multiple slots, which then also limits your CPU choice. I have a gaming motherboard with 4 GPUs (2x GTX 1080 and 2x GTX 1080Ti) and FStorm just blazes through things 🙂

    • tzahi
    • November 12, 2017

    by the way, did you tried to lit your scenes with pure dome+target direct+planes?
    for me it give more controls

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