work-around for slow PT reflection calculation

[Dune]

So you made a SR render layer with just reflections direct/indirect, used that as mask to project generic gradient across PT ground? I have to try that as well.


Meantime, I've done some more tests with several ways of getting a fast reflection on mud. Here are the results. Again, the roughness is the important factor. Above 0.2 it renders much faster, whether it's only metalic, or reflective.

[Kadri]

Ulco can you post the scene you use above. Or anything we can test together here to get a better understanding?

[Dune]

It's on page 3: https://planetside.co.uk/forums/index.php/topic,29012.msg286160.html#msg286160

[Kadri]

Hmm...The polysphere or whatever is a new object i think. I don't get that in my old version.

[Kadri]

The newer versions of Terragen are now quite different then the older ones.
In the past you got errors but it rendered mostly.
I am trying to change the scene with the free version to be able to use it with my older one.
But it is harder. There are parts that makes Terragen crashing (my old version).

[Dune]

Yes, polysphere is new, sorry about that. But it's a very basic file, so you should be able to translate it to your version.

[Kadri]

Couldn't make a closer look i wanted and got only this Ulco.
A direct comparison is not quite possible but still could be useful maybe.
This is an exported object from my old version and rendered in the free new version with the Path tracer (25 landscape).

I tried to use the reflective shader before and there was a huge difference.
This time i used only the default shader with your power f. nodes.

Render time is 1 minute 32 seconds (1280x720 MPD 0.6 AA 6).

It won't be a direct comparison but curious how long your normal scene would render with this default shaders.

If you want to try this, use this for the object and for the ground together (my scene you see here is only one object) and with AA 6 .

[WAS]

My test was actually just projecting the outputted direct and indirect EXRs on a the same terrain but no reflections. Just child layers masked by same image in grayscale with gamma adjustment on it with colour adjust. Also adjusted gamma on the EXRs themselves as they kinda apply dark for some reason.

[Dune]

What should I use for the object? There's nothing in your post.
I'm rendering something now, but will post results tomorrow (dinner time). I managed to export a 500MB terrain, import it, so that works at least.

[WAS]

I used default terrain, no object. A reflection-less ground renders speedy in PT. I think with the object version the idea is to apply the same shaders you'd use for the original ground and should have savings based on the set geometry

[Kadri]

What should I use for the object? There's nothing in your post.
I'm rendering something now, but will post results tomorrow (dinner time). I managed to export a 500MB terrain, import it, so that works at least.

There is a tgc file.

[Dune]

Okay, I'll check that out first. What I did yesterday is point an orto cam down on an area just in front of the main cam, kill all lights and atmo, render to dsik after setting micro export. Turned out I still had the stones and wrong cam, so a piece of geo was a 'strip' towards horizon, with all polyspheres also present. I'll have a better go today.
@WAS , yes, without reflections a piece of ground renders pretty fast, but I was initially deterred by the long rendertimes due to (I think) low roughness (<0.2) reflective ground. And that is not necessary after all. But anyway interesting to see how exporting works, and whether rendering indeed speeds up over an obj.
Also interesting to be able to sculpt additional stuff into the geometry, which might be needed for some work.

[Dune]

I rendered an object at mpd=1 from the main cam (crop of front area) in 3mins, but the file is probably too big; 3gigs. If I load into TG, it says; can't find file. But I can get inside. So I don't know what's happening, but I'll try a smaller file size.

[WAS]

Thats the issue I am having with stuff over 2gb. Matt says he is fixing that though.

[Dune]

I forgot about that. But now I've made a smaller crop of 250MB, which is now imported and rendering. But it's not as simple to just feed all shaders into the color input of the default shader, as the reflections won't be covered. It needs more work to get a real comparison between microply render and obj render. For now I just added a reflective shader at roughness 0.1 and see how fast that goes.