Cryengine is Free...

[HMart]

Sorry I don't have much time to see the full video but what I saw in the first few minutes where he built a room, is nothing special, I've done the exact same workflow for example in Max Payne 2 editor.

What he means with mesh's, is that the geometry you work with inside that Unreal Engine plugin, is the same one you do when you work in say Blender, Maya, etc, is just triangles and quads. Meaning the geometry is not composed of simple mathematical planes like brush's but real 3D geometry. 

Why you don't use portals in there? Because Unreal Engine 4/5 afaik have no portal system for visibility culling.

Portals are a CPU concept and are normally used to prevent to render things that the player doesn't see during gameplay, but is not the only way to do this job. I think ever since UE4? Epic's engine uses a more advanced system (but more expensive one) called GPU occlusion queries, in simplistic broad terms, it uses the GPU to do "porteling" automatically for you. btw Unreal Engine also used CPU based, manually placed portals not that far in the past.

Also the idTech4 BFG fork RBDoom3BFG engine also supports occlusion queries but on the CPU, using a Intel made library, perfect for open spaces. 

Edited January 6 by HMart

[JackFarmer]

On 1/5/2026 at 4:46 PM, HMart said:

Anyone brave enough can try but TDM license forbids commercialization.  Also the moment that happen, it would be sued by the current Thief IP holders and taken down very fast, why? Because this game is obviously very derivative of Thief.

IMO the only reason that has not happen already, is not the goodness of the Thief IP holders hearts, is the fact this game uses different names and lore from Thief, is totally free and very important the makers of it and the people working on it, are not getting money from any other source, like Patreon for example. So probably falls into some safe "fair use" territory.  

Copyright infringement aside -  I'm not so sure that the former and current owners of the IP are still interested in the original lore: Neither Thief 2014 nor the new VR game make relevant use of Hammerites/Mechanists/Keepers.

Probably there is nobody left working on the franchise who knows about the original story in the first place or they consider it inferior compared to their very creative  new story approaches.

This reminds me of another anectode: I can't remember who it was (I think it was Springs) who was even attending a meeting at Eidos Montreal at the time to discuss a collaboration between TDM/Eidos. As far as I remember, he mentioned here, at least two of his conversation partners didn't even know what “Thief” was. I rest my case.

 

Edited January 7 by JackFarmer

[datiswous]

21 hours ago, HMart said:

Also the idTech4 BFG fork RBDoom3BFG engine also supports occlusion queries but on the CPU, using a Intel made library, perfect for open spaces. 

So I guess we could fork that code over to TDM to make open areas less difficult to work with?

Edited January 7 by datiswous

[Bikerdude]

1 hour ago, datiswous said:

So I guess we could fork that code over to TDM to make open areas less difficult to work with?

What's the catch though, wouldn't we then again be reliant on users owning D3?

[datiswous]

I think you misunderstand. Also, I don't think you need Doom3 with RBDoom3BFG engine.

I mean only porting relevant code over to tdm. this has been done before for other features.

[demagogue]

5 hours ago, JackFarmer said:

This reminds me of another anectode: I can't remember who it was (I think it was Springs) who was even attending a meeting at Eidos Montreal at the time to discuss a collaboration between TDM/Eidos. As far as I remember, he mentioned here, at least two of his conversation partners didn't even know what “Thief” was. I rest my case.

This is referring to TDM's collaboration with Square Enix North America at the time Eidos-Montréal was making the game Thief (Thief 4). SE held a contest of fan material. Basically they wanted to have a contest of fan missions for past "Thief" games and fan art. They did end up having a contest. There were a few TDM entries. Some of us on the team got a free copy of Thief 4 for "participating". 

Well you can see just from that set up that these were the marketing people that really had no idea what Thief really was, and they definitely weren't going to understand the relationship of TDM to Thief IP, although you could clearly tell the moment when the lawyers probably got involved and they changed the rules to be only Thief inspired and they really watered it down since the link to Thief IP itself was lost, and they couldn't be in any way linked to the TDM/idTech4 engine.  

It probably would have been great if it'd been the Eidos-Montréal devs we were working with, since those would have been actual gamers that understand the game & us, our kind of people. But it was the marketing people, the Square Enix NA marketing people at that, and they were just in an entirely different universe. I mean completely detached from the reality of this game that they're working on. They were clearly only interested in the business side and thought of fans as shallow entertainment consumers that they were trying to hype up, like we were the core of Thief 4's target audience. They had this really unreal positivity about this contest while being so clueless about what it was really about. Our communications with them were just bizarre and otherworldly.  

There's another story I can tell about working with a team of lawyers that were pro bono vetting our Version 2.0 release to make sure it cleared id's & Eidos's IP (technically I guess also the asset makers of the assets we were using to replace id's) when we went standalone, or anyway they gave us a memo of all the considerations to look out for in doing it. I made a thread about it, but practically I don't know if it changed that much of what we were doing (the problem kind of solves itself just by our gamers' intuition), and obviously we released it standalone and nothing happened, so it worked out. Actually that Square Enix contest did have one kind of positive result for us, which is we got language from them in writing that seemed to assume we were clear of any claim for Thief IP violations as far as they were concerned. I've kept that message on hand in case we ever do get pushback, but fortunately we never have. 

 

Edit: I'm looking back on this message and thinking about the NoClip documentary on the making of Disco Elysium, which is still coming out these days, and I recall that NoClip contacted us once about making a documentary on our making. Or somebody did anyway. But I think the inside story of the making of TDM would be super cool if anybody did decide to make it. There are so many interesting stories like this. Well I think they're interesting. Maybe one of us should make it. 

[datiswous]

5 minutes ago, demagogue said:

There were a few TDM entries

Actually (tdm mission) Requiem won that contest.

[demagogue]

Right! Great FM too, although I tend to bias on the side of gameplay-heavy FMs over storytelling-heavy ones, and it was definitely the latter. But it was still objectively great & I still really loved it. 

[datiswous]

4 minutes ago, demagogue said:

although I tend to bias on the side of gameplay-heavy FMs over storytelling-heavy ones, and it was definitely the latter.

Well I'm not sure I would agree (I think it has much of both), but maybe it depends on what kind of gameplay you're looking for. Well let's not go into that discussion

Edited January 7 by datiswous

[JackFarmer]

13 minutes ago, demagogue said:

They were clearly only interested in the business side and thought of fans as shallow entertainment consumers that they were trying to hype up, like we were the core of Thief 4's target audience. They had this really unreal positivity about this contest while being so clueless about what it was really about. Our communications with them were just bizarre and otherworldly.  

 

I can vividly imagine this exchange of ideas.

[demagogue]

21 minutes ago, datiswous said:

Well I'm not sure I would agree (I think it has much of both), but maybe it depends on what kind of gameplay you're looking for. Well let's not go into that discussion

I like to talk about it, but yeah it's probably off topic to this thread to get into it.

But yes, it has lots of great gameplay too, so I used the entirely wrong phrasing. For the record, maybe the way to better put it is that it's more cinematic, like with the mise en scene and plot flow design, it's telling a story, which I also like. But I also really like ones that are simulationist, like you're just dropped in an uncaring world that doesn't care where you go & isn't really telling a story, but it has things happening in it that you can observe. This is all nitpicking nuance though. I still agree it's objectively great and I was happy it won & got recognized for how great it is. 

[Petike the Taffer]

On 1/7/2026 at 7:21 PM, demagogue said:

This is referring to TDM's collaboration with Square Enix North America at the time Eidos-Montréal was making the game Thief (Thief 4). SE held a contest of fan material. Basically they wanted to have a contest of fan missions for past "Thief" games and fan art. They did end up having a contest. There were a few TDM entries. Some of us on the team got a free copy of Thief 4 for "participating". 

Well you can see just from that set up that these were the marketing people that really had no idea what Thief really was, and they definitely weren't going to understand the relationship of TDM to Thief IP, although you could clearly tell the moment when the lawyers probably got involved and they changed the rules to be only Thief inspired and they really watered it down since the link to Thief IP itself was lost, and they couldn't be in any way linked to the TDM/idTech4 engine.  

It probably would have been great if it'd been the Eidos-Montréal devs we were working with, since those would have been actual gamers that understand the game & us, our kind of people. But it was the marketing people, the Square Enix NA marketing people at that, and they were just in an entirely different universe. I mean completely detached from the reality of this game that they're working on. They were clearly only interested in the business side and thought of fans as shallow entertainment consumers that they were trying to hype up, like we were the core of Thief 4's target audience. They had this really unreal positivity about this contest while being so clueless about what it was really about. Our communications with them were just bizarre and otherworldly.  

There's another story I can tell about working with a team of lawyers that were pro bono vetting our Version 2.0 release to make sure it cleared id's & Eidos's IP (technically I guess also the asset makers of the assets we were using to replace id's) when we went standalone, or anyway they gave us a memo of all the considerations to look out for in doing it. I made a thread about it, but practically I don't know if it changed that much of what we were doing (the problem kind of solves itself just by our gamers' intuition), and obviously we released it standalone and nothing happened, so it worked out. Actually that Square Enix contest did have one kind of positive result for us, which is we got language from them in writing that seemed to assume we were clear of any claim for Thief IP violations as far as they were concerned. I've kept that message on hand in case we ever do get pushback, but fortunately we never have. 

 

Edit: I'm looking back on this message and thinking about the NoClip documentary on the making of Disco Elysium, which is still coming out these days, and I recall that NoClip contacted us once about making a documentary on our making. Or somebody did anyway. But I think the inside story of the making of TDM would be super cool if anybody did decide to make it. There are so many interesting stories like this. Well I think they're interesting. Maybe one of us should make it. 

I've read about this before here on the forums, even when the contest had just recently concluded, but reading about it in greater detail years later is certainly interesting. Thank you.

It's a pity that it was mostly the marketing people who were involved on the Square Enix side, as I had the impression it was also the devs at EM that had played Requiem and all the other submitted missions and really liked them. I suppose it was as well, but the TDM team mostly heard from the marketing people. 
 

On 1/7/2026 at 7:28 PM, datiswous said:

Actually (tdm mission) Requiem won that contest.

On 1/7/2026 at 7:31 PM, demagogue said:

Right! Great FM too, although I tend to bias on the side of gameplay-heavy FMs over storytelling-heavy ones, and it was definitely the latter. But it was still objectively great & I still really loved it. 

Yes, I wanted to note that as well. I even remember how the people over here in the TDM forums were sort of laughing at the fact that the results of the contest were favourable to TDM and had, in a sense, "proven" TDM as a worthy freeware successor to the Thief IP, with all the modding and mapping tools at one's disposal and so on, whereas Thief 4 or Thi4f or whatever Square Enix were calling it at that point, offered no such possibilities.

The entire contest, while no doubt declared in good will and something I actually appreciated seeing, was such a self-own for Square Enix, ultimately to the detriment of them trying to bring back and market the reboot of an older IP. Even if Thief 2014 was a terrific reboot (which I doubt it would ever be), it would still have been hampered by people learning about modding being impossible, and looking to the trilogy and to TDM instead, to make new Thief-style stealth gaming content. Still, I appreciate they recognized the quality's of Moonbo's Requiem FM. 

Given many retrospectives I've  seen over the years, gradually, on the 2014 Thief reboot attempt, one thing a surprising amount of them shared was noting how the game didn't feel cohesive in concept and execution, at any point. Not only not to the same level as the Thief trilogy, but also not even at the level when you consider it as an individual game, a new game on its own. Errant Signal, who's not some deep Thief fan, replayed the older games and played the reboot back when it came out, and made this exact observation already a decade ago. The reboot was just all over the place, in every department, felt clearly unfinished or rushed, and the most interesting story would be the behind the scenes at Eidos Montreal, on how mismanaged the entire project became over the course of several years. 

I think it's telling that, while even heavily discounted on GOG.com, Thief 2014 hasn't been selling well there, nor attracting much interest, whereas the original trilogy sells for figurative (and sometimes literal) cents on that same site - you can buy the whole trilogy for a smaller price than the reboot, which is kind of hilarious - and continues to have great sales and is considered one of the all-time bestsellers. 

 

On 1/7/2026 at 7:39 PM, JackFarmer said:

I can vividly imagine this exchange of ideas.

Same here.  

I concur with demagogue that the actual Eidos Montreal devs behind Thief 2014, at least those who cared enough to make it at least somewhat presentable and playable - even if the actual game directors never got their act together and never decided on a consistent design approach - those would have been much more interesting to be in contact with, even regarding the fan mission contest.

The sad truth of the matter is that all too many big publishers these days, especially those formed through larger mergers, like the Eidos buyout by Square Enix, are often marketing-first, interest in developers, and veteran players and new players alike, second. I still remember the sheer amount of money spent on pointless external marketing for Thief 2014, all the while that reboot attempt never really coalesced into anything that felt consistent (rather than throwing everything at the wall, in a panic, hoping something would stick), and was also plagued by all manner of technical issues. Just an overall embarassment, and I'm not surprised that even very lenient-leaning game retrospectives of that reboot attempt.

The fact that the Thief IP has been sold away to Nordic Games and Embracer in more recent years, with Square Enix no longer caring about it and other older game IPs, also says a lot. Given the Embracer Group's own woes and bad decisions, I'm not sure any new development team will ever attempt another installment of Thief, even if it was a second reboot attempt. 

Edited January 26 by Petike the Taffer

[Keruah]

On 12/10/2025 at 12:05 AM, chakkman said:

The OP obviously knows of some super secret conversion tools which do the job for him. 

Probably, ChatGPT... 

[Keruah]

I had this idea floating in my head to try and do something similar to TDM in Frictional Games' HPL2 engine (I think the source code is available on GitHub), it was a fun idea to contemplate, cause the first Amnesia TDD had great sound and lighting, afaik. But, it was just an idea, cause I know how much time it takes to finish something like that. For example, the fanmade engine for Morrowind, the OpenMW, has been in development for 17 years and they still haven't implemented everything they want in the engine. So, for this port to even take place, you either need lots of free time OR lots of money, otherwise you'll end up with a project that takes years, and years, and years non-stop with no result in the forseeble future. TDM alreay has an engine that has a solid base for constructing fan missions. Probably not the most sophysticated engine on the planet but great for the game's purposes. 

[HMart]

Yes HPL2 can be considered a nice engine for a Thief 3 plus like game, as it has full real time lighting like TDM engine and even has a better physics engine but it lacks a few cool stuff TDM engine does and it also suffers from almost the same limitations of the TDM engine, as open spaces is concerned.

I feel like a few people here really underestimate how powerful TDM engine really is, yes is old by today standards and it has almost no support for open spaces, but has excellent support for "corridor" games and a very advanced fps controller.

Just a tiny comparation of what I know about both engines, I could really compare way more but imo this should be enough to show that TDM engine isn't as basic as some may assume:

** TDM Engine **
 

Spoiler

Spot lights with soft (or not) stencil and or shadow maps, volumetrics and projected textures.

Point lights with soft (or not) stencil or shadow maps and cube map effects.

Special fog lights, special very cheap non shadow casting lights called blend lights (just does simple Opengl blending).

Directional lights with soft (or not) stencil or shadow maps but afaik only correct shadow casting for stencil...

Dedicated Ambient lights with no shadow support, to give the level a global light brightness and color. No support for normal maps or specular in these and blend lights.

64bits color support.

Somewhat advanced dedicated glass breaking effect.

Some LOD (level of detail) support

Physics engine is very old school, simplistic and doesn't support very complex physics systems apart from ragdolls (thou you can do some cool stuff just with ragdoll support).

Support for POM (Parallax Occlusion Mapping)

Very advanced Mirror surfaces, computer screens and "portal" like effects called "Xray screens" (don't confuse with portals for visibility culling)

Pixel and Vertex Shaders are based on popular GLSL shading language

Advanced multi-threading support using a modern jobs system

etc ...

** HPL2 **

Spoiler

No stencil shadow support.

Spot lights with shadow maps and projected textures.

Point lights, no shadow support for these.

Box lights (aka Ambient lights) with no shadow support as well, to give the level a global light brightness and color.  No support for normal maps or specular in them.

No 64bits color support.

No dedicated glass breaking effect.

No LOD support.

Physics engine is very advanced and powerful, with support for very complex joints and motors and other stuff like cloth and such BUT Frictional Games only implemented a part of it, so just a subset of the Newton 2.X physics engine is really available in HPL2 (similar to what idSoftware did with .lwo model support, where idTech4 only supports a tiny part of that format real power)

Support for POM (Parallax Occlusion Mapping)

No support for Mirror like surfaces, apart from basic water reflections, no special "portal" like effects. 

Pixel and Vertex Shaders are based on niche, old deprecated Nvidia CG language (it does run on AMD and Intel hardware as well)

No out of the box multi-threading support.

Editor tooling is even more simplistic.

etc ...

 

Edited January 9 by HMart

[Petike the Taffer]

On 1/9/2026 at 8:28 PM, HMart said:

Yes HPL2 can be considered a nice engine for a Thief 3 plus like game, as it has full real time lighting like TDM engine and even has a better physics engine but it lacks a few cool stuff TDM engine does and it also suffers from almost the same limitations of the TDM engine, as open spaces is concerned.

I feel like a few people here really underestimate how powerful TDM engine really is, yes is old by today standards and it has almost no support for open spaces, but has excellent support for "corridor" games and a very advanced fps controller.

Just a tiny comparation of what I know about both engines, I could really compare way more but imo this should be enough to show that TDM engine isn't as basic as some may assume:

** TDM Engine **
 

  Reveal hidden contents

Spot lights with soft (or not) stencil and or shadow maps, volumetrics and projected textures.

Point lights with soft (or not) stencil or shadow maps and cube map effects.

Special fog lights, special very cheap non shadow casting lights called blend lights (just does simple Opengl blending).

Directional lights with soft (or not) stencil or shadow maps but afaik only correct shadow casting for stencil...

Dedicated Ambient lights with no shadow support, to give the level a global light brightness and color. No support for normal maps or specular in these and blend lights.

64bits color support.

Somewhat advanced dedicated glass breaking effect.

Some LOD (level of detail) support

Physics engine is very old school, simplistic and doesn't support very complex physics systems apart from ragdolls (thou you can do some cool stuff just with ragdoll support).

Support for POM (Parallax Occlusion Mapping)

Very advanced Mirror surfaces, computer screens and "portal" like effects called "Xray screens" (don't confuse with portals for visibility culling)

Pixel and Vertex Shaders are based on popular GLSL shading language

Advanced multi-threading support using a modern jobs system

etc ...

** HPL2 **

  Reveal hidden contents

No stencil shadow support.

Spot lights with shadow maps and projected textures.

Point lights, no shadow support for these.

Box lights (aka Ambient lights) with no shadow support as well, to give the level a global light brightness and color.  No support for normal maps or specular in them.

No 64bits color support.

No dedicated glass breaking effect.

No LOD support.

Physics engine is very advanced and powerful, with support for very complex joints and motors and other stuff like cloth and such BUT Frictional Games only implemented a part of it, so just a subset of the Newton 2.X physics engine is really available in HPL2 (similar to what idSoftware did with .lwo model support, where idTech4 only supports a tiny part of that format real power)

Support for POM (Parallax Occlusion Mapping)

No support for Mirror like surfaces, apart from basic water reflections, no special "portal" like effects. 

Pixel and Vertex Shaders are based on niche, old deprecated Nvidia CG language (it does run on AMD and Intel hardware as well)

No out of the box multi-threading support.

Editor tooling is even more simplistic.

etc ...

 

Thank you. Interesting.  

All the more interesting for me, as I've been a fan of Frictional Games (and their engine) since the Penumbra Tech Demo and all the first few Penumbra games. I remember when the Amnesia HLP2 engine and the editor for Amnesia missions built in that engine were first showcased to the fans, back in late 2009, early 2010, several months before the game debuted in early autumn 2010. One of the FG fans even commented "Drooling...".

Penumbra wasn't much moddable, as there was no level editor and you had to build everything by hand in Maya or any other appropriate 3D modelling software. There was no HLP2 level editor equivalent, no Dark Radiant equivalent, in HLP1, it had do be done by hand. Now that it's been open-source (IIRC) for over a decade, I wouldn't be surprised if some enterprising indie dev tried to make a rudimentary level editor for it. The HLP2 version of the engine is actually quite similar to the TDM and Dark Radiant approach, though it does even allow for a "non-airtight" approach (i.e. you don't have to fully seal a space with brushes, and even a very rudimentary level will work in the HLP2 engine). 


Some old FG development videos, back when the more user-tools-flexible HPL2 was brand new and Amnesia still had months to go before it was published:

- HPL2 level editor timelapse (this is the video that was commented on with "Drooling..." by that one eager fellow FG old-timer fan)
- use of decals in the HPL2 level editor
- HPL2 material editor
- HLP2 model editor
- HPL2 particle editor

Setting up a custom story level (rather than an expaded total conversion) in HPL2, using the base game assets, with the help of the level editor.

An HPL2 mapper at work, showcasing the phases of building a level in the engine, mainly via the level editor, plus some of the other aforementioned utilities accessible from the editor: 1, 2, 3, 4

Edited January 18 by Petike the Taffer