Author Topic: Displacement issue (problem)  (Read 2005 times)

2022-08-13, 23:18:33
Reply #15

tradstown

  • Active Users
  • **
  • Posts: 108
    • View Profile
Hmm, that's not exactly what i meant. You scaled down the terrain from gargantuan to huge, but it's still too big for Corona displacement to handle in world size mode. Try to make something like in my attachment, where you'd have only few patches of terrain with displace, small enough to safely decrease displacement world size to centimeter, or even lower. You then judge from the closer patch if displacement is fine enough and then look at the farther patch to see if displacement is visible at all at that distance. The idea is to have terrain small enough, so to be sure that Corona does not run out of RAM and not produce artifacts because of it.

Here we are. 0.05m in displacement World size mode. Less number in the setup getting me render of empty scene without displacement and object with this displacement at all.

2022-08-13, 23:28:46
Reply #16

romullus

  • Global Moderator
  • Active Users
  • ****
  • Posts: 7787
  • Let's move this topic, shall we?
    • View Profile
    • My Models
So what do you think? Is displacement looks any better in the distance compared to your previous tests, or it's basically the same?
I'm not Corona Team member. Everything i say, is my personal opinion only.
My Models | My Videos | My Pictures

2022-08-14, 01:16:08
Reply #17

tradstown

  • Active Users
  • **
  • Posts: 108
    • View Profile
So what do you think? Is displacement looks any better in the distance compared to your previous tests, or it's basically the same?

In the distance - yes, but near the camera - no =(

2022-08-14, 10:28:03
Reply #18

romullus

  • Global Moderator
  • Active Users
  • ****
  • Posts: 7787
  • Let's move this topic, shall we?
    • View Profile
    • My Models
Ok, so now when we've establish that the issue is most likely because of displacement limitations and not of something else, we can try to see if it's possible somehow to overcome some of those limitations without waiting when the devs will improve the code significantly. For example, you could try to split your terrain in multiple separate meshes, based on their distance from the camera and add to each of them a Corona displacement modifier with increasingly higher subdivision quality settings. The idea is to try to force farthest away displacement not to degrade so much, so we can see more details and at the same time not to subdivide foreground displacement to the point where it becomes a performance issue.
I'm not Corona Team member. Everything i say, is my personal opinion only.
My Models | My Videos | My Pictures

2022-08-14, 10:32:47
Reply #19

romullus

  • Global Moderator
  • Active Users
  • ****
  • Posts: 7787
  • Let's move this topic, shall we?
    • View Profile
    • My Models
Another idea - maybe you could use Chaos scatter to add some rocks and boulders in the background, so it could look more detailed. You could use Corona distance map in its density slot, so that the scattered rocks would gradually disappear closer to the camera as they would be replaced by the displacement.
I'm not Corona Team member. Everything i say, is my personal opinion only.
My Models | My Videos | My Pictures

2022-08-14, 15:14:31
Reply #20

tradstown

  • Active Users
  • **
  • Posts: 108
    • View Profile
Ok, so now when we've establish that the issue is most likely because of displacement limitations and not of something else, we can try to see if it's possible somehow to overcome some of those limitations without waiting when the devs will improve the code significantly. For example, you could try to split your terrain in multiple separate meshes, based on their distance from the camera and add to each of them a Corona displacement modifier with increasingly higher subdivision quality settings. The idea is to try to force farthest away displacement not to degrade so much, so we can see more details and at the same time not to subdivide foreground displacement to the point where it becomes a performance issue.

I tried to do this, but, for more differences of the ground I used uvw randomizer for the second little displacement, so when I cut all area by pieces, on the render I saw seams because of randomization.
About Corona Scatter - yes, but it can help to add some details like stones, branches etc, but not the structure of the mountains. I hope You understand me. Look at the images please (Aaron's Westwood works). How to get same detalization of the mountains and not use the displacement?
« Last Edit: 2022-08-14, 16:26:44 by tradstown »

2022-08-14, 15:54:47
Reply #21

Basshunter

  • Active Users
  • **
  • Posts: 173
    • View Profile
Is this a known issue for the devs?

Would like to heard a word from them.

2022-08-15, 10:20:00
Reply #22

romullus

  • Global Moderator
  • Active Users
  • ****
  • Posts: 7787
  • Let's move this topic, shall we?
    • View Profile
    • My Models
About Corona Scatter - yes, but it can help to add some details like stones, branches etc, but not the structure of the mountains. I hope You understand me. Look at the images please (Aaron's Westwood works). How to get same detalization of the mountains and not use the displacement?

I thought you are using two displacements, one large scale with little or no tiling for mountains and another small scale highly tilling for rocks and other details and the latter is the one that gives you the most trouble. Isn't that the case?
I'm not Corona Team member. Everything i say, is my personal opinion only.
My Models | My Videos | My Pictures

2022-08-15, 11:02:16
Reply #23

tradstown

  • Active Users
  • **
  • Posts: 108
    • View Profile
About Corona Scatter - yes, but it can help to add some details like stones, branches etc, but not the structure of the mountains. I hope You understand me. Look at the images please (Aaron's Westwood works). How to get same detalization of the mountains and not use the displacement?

I thought you are using two displacements, one large scale with little or no tiling for mountains and another small scale highly tilling for rocks and other details and the latter is the one that gives you the most trouble. Isn't that the case?

You right, I'm using 2 displacements: One - the main structure of the mountains/rocks and another one is for little details (stones that comes out from the ground that we can see near the camera). There is no scatters at all in my tests.
I meant in general, that we can use scatter of course for adding some details, but for now the main test for me is using 2 displacements and details from them near and far from camera. Actually i miss about 3D Displacement.

2022-08-15, 11:46:15
Reply #24

tradstown

  • Active Users
  • **
  • Posts: 108
    • View Profile
So, I found something maybe. I think the main thing of that great Aaron's Westwood works is vertex displacement or voxel displacement. It works in a different way from 2.5D displacement or 3D displacement, what I understood. Maybe I'm wrong, but Corona team, please, check Octane's render displacements. Maybe it will be useful for all of us. In any case, check all this topic for displacement bug, it is real of Real World Units in setup menu. And also check the tessellation when using few displacements in Layered Mtl.

2022-08-15, 15:39:37
Reply #25

maru

  • Corona Team
  • Active Users
  • ****
  • Posts: 11490
  • Marcin
    • View Profile
Could you share an example scene with us here? https://support.chaos.com/hc/en-us/requests/new
We would then look into it and pass it to devs to get their feedback.
Marcin Miodek | chaos-corona.com
Chaos Corona Support Team Lead | contact us

2022-08-15, 16:10:44
Reply #26

tradstown

  • Active Users
  • **
  • Posts: 108
    • View Profile
Could you share an example scene with us here? https://support.chaos.com/hc/en-us/requests/new
We would then look into it and pass it to devs to get their feedback.

Thank you! I'm doing it right now. Have a nice day.

2022-08-15, 18:45:22
Reply #27

PROH

  • Active Users
  • **
  • Posts: 1198
    • View Profile
Hi. I'm not sure what exactly the problem is, but if I  understand you correctly,  you're using a 32000px x 32000px bitmap to displace a 10km X 10km area. If that's correct you have 3,2px pr 1meter and that will never give any detailed displacement result.

This isn't caused by Corona, this will be the same for every renderer.

Hope it helps

2022-08-15, 23:23:06
Reply #28

tradstown

  • Active Users
  • **
  • Posts: 108
    • View Profile
Hi. I'm not sure what exactly the problem is, but if I  understand you correctly,  you're using a 32000px x 32000px bitmap to displace a 10km X 10km area. If that's correct you have 3,2px pr 1meter and that will never give any detailed displacement result.

This isn't caused by Corona, this will be the same for every renderer.

Hope it helps

Hello. Yes, you right for the base displacement. But:
Screen size displacement, as I understand working in depends on what you see on the image (pixels), not on texture of the displacement. And yes, I'm using 32K texture for displacement of 10km ground, but also I'm using 8K resolution texture (3m by 3m) for adding details on the top level after main displacement of the ground and it has tiling. So that is a question, how to save more details far from camera and also get good results near the view. That's why I tried to use Real World (units) displacement.

2022-08-16, 00:46:32
Reply #29

PROH

  • Active Users
  • **
  • Posts: 1198
    • View Profile
OK. So do you use the 32k map as a hightmap for the hole area like it's done in a game engine? If so, then I wouldn't use Corona displacement for this, but either 3dsMax displacement Modifier or some sort of vertex displacement (depending on the mesh structure).

Regarding the tiled 3x3m map, it's likely to small to be seen from 1 km or more.