Rendered using 4.3.08.frontier.
- Enabled "path tracing on surfaces" in the Advanced tab of the renderer
- Enabled "robust adaptive sampling (BETA)" in sampling settings
Comparison: "path tracing" vs. "standard renderer"
Here's the scene file (reduced AA to 2 for faster rendering).
Requires Terragen 4.3.08 or higher.
Lovely lighting but glass shader does not work with these settings and render time is much slower.
Glass shader not working at all! Worked with previous frontier version
Comparison Pics - build 4.3.08.frontier
No Path Tracing
[attach=1]
With Path Traing
[attach=2]
Glass shader not working properly in either!
Transparency doesn't work with the path tracer yet. But what does it look like in previous builds?
Path tracing?! Matt, I love you!. The time penalty is a bit hefty, however... any chance PT will be faster in the future?
BTW, I see new beta exe's being dropped regularly but don't see a change log... is there any place I can see what's new in recent versions?
It should be a mad blue green glass.
Sorry should be medium. Typing in a car
Quote from: pokoy on September 27, 2018, 07:19:47 AM
Path tracing?! Matt, I love you!. The time penalty is a bit hefty, however... any chance PT will be faster in the future?
Yes it will continue to get faster as I make it smarter.
Quote
BTW, I see new beta exe's being dropped regularly but don't see a change log... is there any place I can see what's new in recent versions?
If you use Check for Updates in the app, the frontier builds should be presented as an optional update (for Pro and Creative users). From there you can see the change log.
...but if you have already installed an update, you can find the change log in the Docs or Documentation folder inside the program folder.
I see - thanks! Will frontier builds replace stable builds or can they be installed side by side?
PT - will TG get unified sampling at some point? We have a few places to set sampling which is prone to user error. Also, it can be hard to tell which sampling contributor is responsible for high render times if you need to get them down. But I imagine this is quite a task...
There are so many reflection projects/experiments I want to try this on >.< From what I can tell, this is the sort of interaction from TG I've been looking for when developing some materials.
Will path tracing be able to handle surfaces and objects separately to allow transparency in some instances while using path tracing?
Going to play with this in freeware version and try to play with reflection setting and techniques to see how close I can get without path tracing.
The extra light bouncing with shadowed reflections is really the highlight of this example. The subtleties are just beautiful. Here is the original low-light version in 4.2 which of course just lacks this beauty.
I'm really curious how the Path Tracer looks on those brass shaders now because of their mixing of reflections and masking.
Quote from: pokoy on September 27, 2018, 02:06:26 PM
I see - thanks! Will frontier builds replace stable builds or can they be installed side by side?
As far as installation is concerned, Frontier builds are no different from Release builds. They will both default to the same program folder (Terragen 4). If you try to install to a different folder it will still remove the old one.
However, you can have multiple versions installed. I always install the latest build to the default location, but before I do, I copy and paste the existing version to new folder. They all sit in C:\Program Files\Planetside Software. The latest is called Terragen 4. Earlier versions are called something different, e.g. Terragen 4 - 4.2.10
For me this makes installing multiple versions pretty straightforward and I can choose default install settings every time.
Quote from: pokoy on September 27, 2018, 02:06:26 PM
PT - will TG get unified sampling at some point? We have a few places to set sampling which is prone to user error. Also, it can be hard to tell which sampling contributor is responsible for high render times if you need to get them down. But I imagine this is quite a task...
Yeah, I'm working on this problem, bit by bit.
Generally with path tracing enabled I reduce sunlight soft shadows to between 1 and 4. But I would like to make this automatic in future.
Cloud voxel scattering quality (in GI Settings) seems to be most efficient in the 100-150 range.
With atmosphere samples the optimal value varies a lot.
Use "robust adaptive sampling" with default settings to let the renderer ramp the AA up and down as much as it needs to, otherwise the above recommendations may not be good after all.
Quote from: WASasquatch on September 27, 2018, 04:30:17 PM
I'm really curious how the Path Tracer looks on those brass shaders now because of their mixing of reflections and masking.
This is one of your materials, WAS. I may have modified it but I don't think so. I realise that you intended the reflections in your material to be sharper, but the path tracer unifies the roughness of specular highlights with the roughness all other specular reflections so they are physically correct. To get closer to your intended look, we might have to mix a very low roughness reflection with a medium roughness reflection to add some spread to the highlights.
Quote from: Matt on September 27, 2018, 08:12:42 PM
Quote from: WASasquatch on September 27, 2018, 04:30:17 PM
I'm really curious how the Path Tracer looks on those brass shaders now because of their mixing of reflections and masking.
This is one of your materials, WAS. I may have modified it but I don't think so. I realise that you intended the reflections in your material to be sharper, but the path tracer unifies the roughness of specular highlights with the roughness all other specular reflections so they are physically correct. To get closer to your intended look, we might have to mix a very low roughness reflection with a medium roughness reflection to add some spread to the highlights.
I see what you mean, though I have to say, again these reflections in path tracing are gorgeous. It also seems that highlights coupled with specular don't seem to gain too much vibrancy. In some instances I notice reflected specular almost gets too rich in colour as if added light rays.
Thank you for showing me.
I should make it clear that all the highlights in this scene are simply reflections of bright luminous cards, so you don't see anything responding to "specular highlight" in the shader, although it does use that roughness value.
The saturation of multiple reflections is caused by compound multiplication of the RGB reflectivity values, and this happens in the standard renderer too.
Quote from: Matt on September 27, 2018, 09:25:19 PM
I should make it clear that all the highlights in this scene are simply reflections of bright luminous cards, so you don't see anything responding to "specular highlight" in the shader, although it does use that roughness value.
The saturation of multiple reflections is caused by compound multiplication of the RGB reflectivity values, and this happens in the standard renderer too.
"
Oh I see. I frogot to mention the light from that card looks really nice. Unfortunately these path tracing benefits won't be seen on clouds will they? No reflections obviously-but light interaction
Quote from: mhaze on September 27, 2018, 08:55:00 AM
It should be a medium blue green glass.
I haven't found anything wrong with the glass shader in standard rendering mode. Have you rendered this exact scene in an older version? Can you send us a setup?
Quote from: WASasquatch on September 27, 2018, 11:25:57 PM
Oh I see. I frogot to mention the light from that card looks really nice. Unfortunately these path tracing benefits won't be seen on clouds will they? No reflections obviously-but light interaction
Cloud-to-cloud lighting isn't affected. Cloud Layer v3 and Easy Cloud are shaded using their own system which uses a combination of path tracing and voxel caches, but it's independent of "path tracing on surfaces" (except for subtle differences when clouds are illuminated by surfaces).
Hello everyone,
What is for now the rendering time difference (between the old renderer and the new pathtracer one) with a heavy scene, with a lot of trees, grass, rocks ?
Also, is the Ambient occlusion still effective when using pathtracer renderer (or at least as an option) ?
David.
Hi Matt, Sent to planetside support.
Just done a quick check. I'm getting glass but no colour. I've just discovered I had double sided surface turned on this seems in the latest version of TG to cause the colour not to show but works ok in the old version.
Antoine, Path Tracing is currently much slower, though in some cases it produces much more realistic results in subtle bounced lighting. I would recommend simply testing it on a low resolution render or a crop area, that's the only real way to know how much slower it would be on your scene.
We have an option for "Exaggerate surface details" in the GI settings that *only* works with the path tracer rendering method and can use Ambient Occlusion to create these details. But keep in mind this is not as accurate as the path tracer alone. Ambient Occlusion in particular only darkens, it does not handle bounced direct light off surfaces. It may be a pleasing visual effect of course, it's just less realistic.
Mhaze, I hadn't seen your update when I sent the support reply. However I can't replicate the issue, Double-sided is what causes the issue and behaves the same in 4.2 vs. 4.3. Are you sure it used to work?
- Oshyan
Thank you for your explanations Oshyan.
David.
So what exactly is path tracing? :( There's no mention of it in the wiki.
I don't think I can explain it any better than:
https://www.youtube.com/watch?v=frLwRLS_ZR0
And:
https://en.wikipedia.org/wiki/Path_tracing
As far as what is unique about it for Terragen, the current rendering method uses a "GI Cache", which is a method for calculating indirect lighting that relies on a pre-rendering phase which *roughly* calculates the potential for light bouncing in the scene and then holds onto that information in memory. The renderer then references that pre-calculated cache during rendering. Path Tracing, on the other hand, directly traces the path of light for every sample (which can be done multiple times per pixel), and thus is a more accurate approach, though understandably slower.
We probably won't be recommending use of the path tracer as a primary renderer for a little while yet.
- Oshyan
Damn that's clear. Good ol Disney. Good ol ILM. Good ol Pixar. Oh ffs, whoever they are these days, well done them.
The concept of rendering anything is hard to explain to my mates back home so this could help.
;D
Quote from: Oshyan on October 04, 2018, 10:45:23 PM
As far as what is unique about it for Terragen, the current rendering method uses a "GI Cache", which is a method for calculating indirect lighting that relies on a pre-rendering phase which *roughly* calculates the potential for light bouncing in the scene and then holds onto that information in memory. The renderer then references that pre-calculated cache during rendering. Path Tracing, on the other hand, directly traces the path of light for every sample (which can be done multiple times per pixel), and thus is a more accurate approach, though understandably slower.
This is a little bit confusing to me.
If I understand correctly this holds true for bi-directional path tracing (BDPT), but not for TG's unidirectional path tracing?
Read the Wikipedia page on path tracing and look at the section on BDPT. PT is just the "gathering" part, and it is done for every pixel.
Finally found some time to test path tracing on older files. I don't really know where to post this, so here it is; two path traced old files. The one with the rock wasn't really the one I meant to render (it's not that nice), but okay, here it is anyway. The other one took 3.5 hours at detail 6 AA6, soft shadows, focal blur, etc.
Very nice Ulco, definitely noticeable difference in shadows. The second really comes together nicely with the shadows behind the wood and in the trees.
Excited to see more from this. I wonder if glass will be working by the time it's out of frontier?
Hard to say without seeing a direct comparison of same image without PT, but these do look pretty nice, especially in foliage.
- Oshyan
Of course. Here they are. I may have edited out the DOF-GISD artifacts that appear with normal rendering, and used different post-contrast settings in PS, though.
Yeah path tracing does look better imo. Trees just seem stale without it now, to be honest. :O
I am curious how that structure in the second image would look path traced with subtle a non-ray traced reflection to the wood.
The cliff scene is hard to see much benefit in, especially with the differing processing. But the other looks notably nicer with PT, better character and vegetation shading, and nicer shadows on the dead tree, etc.
- Oshyan
Yeah. It's definitely a huge step forward, but I don't see myself rendering a 12m museum wall with Path trace at this moment :P I just hope Matt can bring speed up in due time.
I was also wondering; if you check path tracing the GISD is still on. Should that not be automatically turned off, or doesn't it work anyway in path tracing, whether checked or not?
It seems to me that GISD only works if "standard renderer" is checked, so even if it's on, it doesn't apply with path tracing. Same thing for "exagerate surface details, it only works when path tracing on surfaces is checked.
By the way is there a difference between GISD and exagerate surface details in term of ambient occlusion effect ?
David.
Quote from: Antoine on October 10, 2018, 04:26:53 AM
It seems to me that GISD only works if "standard renderer" is checked, so even if it's on, it doesn't apply with path tracing. Same thing for "exagerate surface details, it only works when path tracing on surfaces is checked.
By the way is there a difference between GISD and exagerate surface details in term of ambient occlusion effect ?
David.
I believe Oshyan or Matt mentioned Exaggerate Surface details is more of AO effect, and less accurate than GISD that takes environment into account.
It's exactly the same thing, but we call it "exaggerate" because with path tracing you shouldn't need to use it, and using it makes the render less realistic.
Quote from: Dune on October 10, 2018, 02:36:06 AM
Yeah. It's definitely a huge step forward, but I don't see myself rendering a 12m museum wall with Path trace at this moment :P I just hope Matt can bring speed up in due time.
I was also wondering; if you check path tracing the GISD is still on. Should that not be automatically turned off, or doesn't it work anyway in path tracing, whether checked or not?
What build are you using? There are two sets of GISD settings; one for "standard renderer" and another for path tracing. The latter is not realistic to use, so it's disabled by default, but we offer it because some people want to use it anyway.
4.3.09. I see the two sets, with the lower being disabled, but I was just wondering if the top one (GISD) still works with path tracing and whether I should manually turn that off (beacuse it would be "double"), or that it's not working by definition anyway. I didn't pay attention to the final seconds of the render phase, or I would have known.