PBR ground, unusable due to jagged shadows

Discussion related to terrain/scenery design.
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mole_man99
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Joined: Sat Nov 25, 2017 9:06 pm

PBR ground, unusable due to jagged shadows

Post by mole_man99 »

Hi

I have been adding PBR ground textures to a freeware scenery I develop. The general effect is more interesting than specular, but I find I must abandon it for now as the PBR seems to create very jagged shadow cast on it. AI aircraft for example, and the jagged nature makes for a flickering effect when moving.

I did some test taking the groundplane back to basic. Below are two shots of a plane with a diffuse, no texture. You can see how much more jagged the PBR version shadow is.

Image

Image

This is with P3dv4.5, default shaders.

I have tried all combinations of setting, in creating the bgl, and in the sim.

It happens on stock install on development machine (zero add-ons) and on my simming machine with various add-ons.

Nvidia 750 GTX on development machine
Nvidia 1080 Ti on sim machine.

Any solutions, apart from not using pbr ground?
mole_man99
Posts: 34
Joined: Sat Nov 25, 2017 9:06 pm

Re: PBR ground, unusable due to jagged shadows

Post by mole_man99 »

I increased the shadow map values in cfg. It seems to make little difference to jagged shadows on pbr ground.

OPAQUE_SHADOW_TEXTURE_SIZE=8192
TRANSLUCENT_SHADOW_TEXTURE_SIZE=4096
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Rob McCarthy
Lockheed Martin
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Re: PBR ground, unusable due to jagged shadows

Post by Rob McCarthy »

Hello,

Shadows should be handled the same way in both of these cases. Are there any other notable differences in the ground textures aside from PBR? If you can create a test file as an add-on you can PM me a link and we can take a look.

Regards,
Rob McCarthy
Rob McCarthy
Prepar3D® Core Lead
mole_man99
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Re: PBR ground, unusable due to jagged shadows

Post by mole_man99 »

The ground above is just a plane with diffuse colour. No texture to rule that out (happens with textures added too). The only texture setting difference between the two is PBR False or True.

I'll set something up at a default airport and send by PM, so you can test it easily.
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downscc
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Re: PBR ground, unusable due to jagged shadows

Post by downscc »

"Diffuse color," isn't this the answer to your question why? The PBR is reliably doing what it is supposed to do with a diffuse light source verses a single light source.
Dan Downs
KCRP
mole_man99
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Re: PBR ground, unusable due to jagged shadows

Post by mole_man99 »

It also happens if a texture map is attached. LM have some files to test. Perhaps it is just me.

The shadows do not AA when projected onto PBR surface it seems.
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downscc
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Re: PBR ground, unusable due to jagged shadows

Post by downscc »

mole_man99 wrote: Wed May 22, 2019 5:23 pm It also happens if a texture map is attached. LM have some files to test. Perhaps it is just me.

The shadows do not AA when projected onto PBR surface it seems.
That makes sense but I think there is more going on there than just aliasing. It looks pretty jaggy, more like a loss of resolution to me. Hope LM can pinpoint what is happening.
Dan Downs
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mole_man99
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Re: PBR ground, unusable due to jagged shadows

Post by mole_man99 »

I do up the shadow map quality in cfg file. 4096 opaque and 2048 translucent. It gets nice shadows with not much performance impact. Perhaps the shadows on pbr ignore this setting in cfg?

Just a thought for the investigation.
mole_man99
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Re: PBR ground, unusable due to jagged shadows

Post by mole_man99 »

Hi Rob

Did you get the link to files in the PM? It sits in my outbox folder but does say sent.
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