Recent posts

#11
Terragen Discussion / Re: Specular map .mtl syntax f...
Last post by PuffnStuff - March 28, 2026, 07:46:41 AM
Hi, Kipper -

Thanks for the response! Score. I spent a bit of time experimenting with .mtl imports over the last few weeks, and it seemed that getting a spec map loaded just didn't work - the only way was to manually load it. Which is fine. I was just looking for a way to streamline the workflow.
#12
Terragen Support / Re: Server ?
Last post by Matt - March 24, 2026, 04:03:15 PM
@raymoh  I have sent you a Personal Message. Please check your inbox here on the forums. I'd like some additional info to diagnose your license issue. Thanks.
#13
Terragen Support / Re: Server ?
Last post by Matt - March 24, 2026, 03:43:34 PM
In that case it might be a bug in how Terragen is dealing with the server, or I'm misremembering a detail of how it works in recent versions. I'll look into this.
#14
Terragen Support / Re: Server ?
Last post by raymoh - March 24, 2026, 02:42:39 PM
Thank you for your explanations. The fact remains:
When I start Terragen, I suddenly get a message on the Splashscreen that my license has expired 5 years ago (!) ... Then I just have to go to the Terragen website and see that it is down.
When it works again, Terragen also starts normally, without any message. This behavior is (for me) reproducible every time the website is down. If my license seems to be expired, the website is down or vice versa: If I first see that the website is down, I will definitely get the message that my license has expired.
#15
Terragen Support / Re: Server ?
Last post by Matt - March 24, 2026, 02:16:17 PM
I also want to mention that Terragen doesn't need to access the server very often. Terragen uses the license key file (.lic file) cached on your hard drive most of the time, and if the cached key file is valid and not expired then it can run without the server. It only needs the server if you are on a subscription plan and you're past the renewal date, or if you're on a perpetual license and attempting to run a version of Terragen that's newer than the maintenance expiry date cached in the key file. In those situations it needs to look at the server to see if the license was renewed. If it was renewed it will re-cache the key file to your hard drive. It checks at other times too, just to be proactive (up to a day before expiry, and at other times when checking for software updates), but those proactive checks should not interrupt your work if they fail to connect.

Still, if the server is having trouble on those rare occasions when Terragen needs to obtain the updated key file, that is unacceptable, so we're going to improve this.
#16
Terragen Support / Re: Server ?
Last post by Matt - March 24, 2026, 01:03:57 PM
Hi Raymoh,

Recently the main server has seen occasions where it was hit by large numbers of requests in a short time, with IP addresses often pointing to large AI companies. We've noticed some temporary outages as a result of this.

If license availability is being disrupted then that is unacceptable and we need to do something about it, so thank you for bringing this to our attention.

We're investigating possible solutions now.

#17
Terragen Discussion / Re: Custom GPT for Terragen
Last post by Dune - March 24, 2026, 02:29:45 AM
The tunnel story was fun to ask, as I knew it wouldn't be straightforward. GPT says a lot of nonsense sometimes, I'd never rely on it. 
It is possible to make a tunnel like a mine shaft, but it's awkward. Bearing in mind that the surface of the planet is a thin, warpable sheet, you can use vector displacement (either within TG with some ingenious nodes, or from an outside painted vector displacement map) to bend two parts together 'underground' and let them intersect eachother. Then use a default shader's opacity slot and a rotated simple shape to make part of the intersection transparent, and you can see through the tunnel.
If you use painted shader or rotated simple shape from either side of a mountain or ridge to bend the mountainside inward, let two sides intersect, and do the same, you can have a 'normal' tunnel.
Or build one from a set of overlapping cubes, all displaced by the same fractal set.
Terragen is pretty versatile, but AI hasn't beaten it yet.
#18
Terragen Discussion / Re: Custom GPT for Terragen
Last post by Kevin Kipper - March 23, 2026, 03:15:41 PM
Yeah, so obviously ChatGPT doesn't actually use Terragen. Several of the suggested nodes above don't even exist within Terragen.  I'd have to say that probability that its answer was correct is exactly 0%.

Granted, it would be nice to be able to tunnel through a procedural terrain with some kind of boolean node, but for now I think you would have to export a portion of the terrain as a mesh, then construct your tunnel in a 3d modeling app, and import the mesh back into Terragen.  

#19
Terragen Support / Server ?
Last post by raymoh - March 22, 2026, 03:38:13 PM
Recently, there have been more and more disruptions/interruptions on your server, resulting in Terragen constantly complaining that the "license has expired" or the app doesn't start at all and the website is no longer accessible. It would be great if you could get this under control again. It's getting annoying over time.
However, if this is just normal server maintenance, it would be nice if you at least communicated this.
#20
Terragen Discussion / Re: Specular map .mtl syntax f...
Last post by Kevin Kipper - March 20, 2026, 01:28:57 PM
Great question.  I've done some research on this in the past and hopefully this may help.  Here's an example for one surface of an object exported in OBJ format and its associated MTL file.

newmtl Sidewinder_NotSmooth
Kd 0.95 0.95 0.95
Ke 1 0 1
Ka 1 1 0
Ks 0.5 1.0 1.0
Ns 500
Tr 0
d 0.5
Ni 1.123
Tf 0.5 0.2 0.8
map_Kd Z:/Library/Images/Vehicles/Air/Sidewinder_Missile/SidewinderMissile_SubPainter_v001_Color_1001.png
map_Ke Z:/Library/Images/Vehicles/Air/Sidewinder_Missile/SidewinderMissile_SubPainter_v001_Normal_1001.png
Bump Z:/Library/Images/Vehicles/Air/Sidewinder_Missile/SidewinderMissile_SubPainter_v001_Height_1001.png
map_Ks Z:/Library/Images/Vehicles/Air/Sidewinder_Missile/SidewinderMissile_SubPainter_v001_Metallic_1001.png
map_Bump Z:/Library/Images/Vehicles/Air/Sidewinder_Missile/SidewinderMissile_SubPainter_v001_Height_1001.png
map_Ns Z:/Library/Images/Vehicles/Air/Sidewinder_Missile/SidewinderMissile_SubPainter_v001_Roughness_1001.png
map_d Z:/Library/Images/Vehicles/Air/Sidewinder_Missile/SidewinderMissile_SubPainter_v001_Normal_1001.png
map_Pm Z:/Library/Images/Vehicles/Air/Sidewinder_Missile/SidewinderMissile_SubPainter_v001_Metallic_1001.png
map_Pr Z:/Library/Images/Vehicles/Air/Sidewinder_Missile/SidewinderMissile_SubPainter_v001_Metallic_1001.png
map_Ps  Z:/Library/Images/Vehicles/Air/Sidewinder_Missile/SidewinderMissile_SubPainter_v001_Metallic_1001.png


In a PBR Metallic Roughness workflow the metalness image provides the specular information.

You'll want to assign the image associated with the MTL's map_Ks parameter to the Default shader's Metalness image parameter in Terragen.  Currently Terragen does not automatically do this; but this behavior may be updated in the future.   The Metalness parameter should be set to a value of 1 because all three of the Default shader's metalness parameters are multiplied together for the final value.

The Default shader automatically maps the MTL's Ks value to the Default shader's Fresnel Reflectivity parameter.