Rendered with path tracing in 4.3.08.frontier

Started by Matt, September 27, 2018, 04:34:15 AM

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Matt

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.
Just because milk is white doesn't mean that clouds are made of milk.

Matt

#16
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.
Just because milk is white doesn't mean that clouds are made of milk.

Matt

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.
Just because milk is white doesn't mean that clouds are made of milk.

WAS

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.

Matt

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.
Just because milk is white doesn't mean that clouds are made of milk.

WAS

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

Matt

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?
Just because milk is white doesn't mean that clouds are made of milk.

Matt

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).
Just because milk is white doesn't mean that clouds are made of milk.

Antoine

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.

mhaze

#24
Hi Matt, Sent to planetside support.

mhaze

#25
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.

Oshyan

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

Antoine

Thank you for your explanations Oshyan.

David.

N-drju

So what exactly is path tracing? :( There's no mention of it in the wiki.
"This year - a factory of semiconductors. Next year - a factory of whole conductors!"

Oshyan

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