Split Topic: Re: Black Spots on the Water

Started by WAS, July 27, 2019, 02:15:53 pm

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WAS

July 27, 2019, 02:15:53 pm Last Edit: July 27, 2019, 02:39:00 pm by Matt
I'm honestly not sure why the Ray Detail Multiplier isn't set to 1 by default, and let people adjust as needed. For the freeware version, without this set to 1, you get black tears in most your renders, sand, water, seams of planes, lateral, normal, etc.

Even when you render at MPD .6 AA 0.6 with cache sliders at, or above max.

And considering I'm on "comparatively low-end hardware" there is really no impact beyond maybe a minute or two in render time (if that). So. Yeah...
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Matt

"Black tears in most your renders" seems highly unusual to me. In general, most renders will come out just fine with the default Ray Detail Multiplier of 0.25. If you recommend increasing it across the board, that could be quite harmful to some people. Sometimes it needs to be adjusted, yes, but the render time can sometimes increase a large amount if you change this setting. Sure, on many renders the time difference will be only a couple of minutes or less, but those aren't the render times we're concerned about. In more complex renders the render times are dominated by the subdiv cache, and in these cases it's important that the default is not too high.
Just because milk is white doesn't mean that clouds are made of milk.

WAS

July 27, 2019, 04:26:31 pm #2 Last Edit: July 27, 2019, 04:29:37 pm by WASasquatch
Quote from: Matt on July 27, 2019, 02:52:50 pm
"Black tears in most your renders" seems highly unusual to me. In general, most renders will come out just fine with the default Ray Detail Multiplier of 0.25. If you recommend increasing it across the board, that could be quite harmful to some people. Sometimes it needs to be adjusted, yes, but the render time can sometimes increase a large amount if you change this setting. Sure, on many renders the time difference will be only a couple of minutes or less, but those aren't the render times we're concerned about. In more complex renders the render times are dominated by the subdiv cache, and in these cases it's important that the default is not too high.


What do you mean by harmful? If my system is so antiquated and have no issues with it, I'm not sure I follow.

What is a more complex render? I do extreme displacement with TG procedurally until it chokes compared to most people using it as a renderer for objects and heightmaps (this seems to be the direction TG is moving in general, away from procedural out of the box landscapes in the field). Lol

And by black tears, I mean those holes, as they are technically tears to the underlying objects core, since if there is a path to the horizon, it'll be white/blue.

Particularly if you have smooth shapes these really show and are noticeable.
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WAS

July 27, 2019, 04:33:14 pm #3 Last Edit: July 27, 2019, 04:49:07 pm by WASasquatch
Take The First Seers recent share for example.

In the straight lines with the blue glow, and in some of the rough of the orange monoliths you can see absolute black where it should have texture colour applied. Doesn't seem to be shadow, especially in the instance of the illumination. There's even some block spots in the lines completely broken away from the displacement
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Matt

Quote from: WASasquatch on July 27, 2019, 04:26:31 pm
What do you mean by harmful? If my system is so antiquated and have no issues with it, I'm not sure I follow.


But you do have issues with it. Your scene with inter-reflecting displaced spheres was particularly challenging to render, but I think it used Ray Detail Multipier 1.0 (correct me if I'm wrong). This is an example of a scene that relies more heavily on the subdiv cache, and it would render in a fraction of the time if the Ray Detail Multiplier had been left at the default value of 0.25.

Quote
What is a more complex render? I do extreme displacement with TG procedurally until it chokes compared to most people using it as a renderer for objects and heightmaps (this seems to be the direction TG is moving in general, away from procedural out of the box landscapes in the field). Lol


See above.

Quote
And by black tears, I mean those holes, as they are technically tears to the underlying objects core, since if there is a path to the horizon, it'll be white/blue.

Particularly if you have smooth shapes these really show and are noticeable.


Those are not caused by Ray Detail Multiplier. They might be fixed by some of the other settings in Subdiv Settings, which perhaps we could change the defaults on, but that would lead to different problems. More info here: https://planetside.co.uk/wiki/index.php?title=Render_Subdiv_Settings
Just because milk is white doesn't mean that clouds are made of milk.

WAS

July 27, 2019, 06:43:24 pm #5 Last Edit: July 27, 2019, 06:46:00 pm by WASasquatch
Quote from: Matt on July 27, 2019, 06:28:56 pm
Quote from: WASasquatch on July 27, 2019, 04:26:31 pm
What do you mean by harmful? If my system is so antiquated and have no issues with it, I'm not sure I follow.


But you do have issues with it. Your scene with inter-reflecting displaced spheres was particularly challenging to render, but I think it used Ray Detail Multipier 1.0 (correct me if I'm wrong). This is an example of a scene that relies more heavily on the subdiv cache, and it would render in a fraction of the time if the Ray Detail Multiplier had been left at the default value of 0.25.

Quote
What is a more complex render? I do extreme displacement with TG procedurally until it chokes compared to most people using it as a renderer for objects and heightmaps (this seems to be the direction TG is moving in general, away from procedural out of the box landscapes in the field). Lol


See above.

Quote
And by black tears, I mean those holes, as they are technically tears to the underlying objects core, since if there is a path to the horizon, it'll be white/blue.

Particularly if you have smooth shapes these really show and are noticeable.


Those are not caused by Ray Detail Multiplier. They might be fixed by some of the other settings in Subdiv Settings, which perhaps we could change the defaults on, but that would lead to different problems. More info here: https://planetside.co.uk/wiki/index.php?title=Render_Subdiv_Settings


That angle issue seems to be erroneous in some other facet and not subdiv, as it did render in a fraction of the time in all other scenarios. That exact angle I was at seemed to have some strange issue, like you said inter-reflective properties. The goal of the support was trying to get that angle which I wasn't able to reproduce. It renders absolutely fine ... Over quarter of the final image in 10-20 minutes compared to 8+ hours (in that one situation) lol

I see. I always get much cleaner angles with it set to 1. For example the share I sent to Hetzen in square noise is base 0.25 and jagged. With it 1 the displacement lines of the colour based displacement are dramatically smoother. I'm rendering his new function right now but will try and share a comparison of lines.

My concrete pathway also needed it set to 1 or the concrete edges were too jagged.
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