Displacement issue

[hunter1st]

Hi guys, I'm having an issue with displacement. I'm getting these weird subdiv lines on the brick and i cant get rid of that open edge.

my first time using displacement in corona

any suggestions?

thanks


EDIT: i've managed to get rid of the lines. I had a subdivide on the wall with noise with is my usual workflow in vray. turning off fixed that issue. so just the open edge now?

[gabrielefx]

in Octane for Max this issue is caused by a wrong scale setting
It's the lack of double precision gpus path tracing. That unstitching you see can't be computed.
Also in Octane there is a rayipslon bias control. I donno if it exists in Corona.

regards

[hunter1st]

in Octane for Max this issue is caused by a wrong scale setting
It's the lack of double precision gpus path tracing. That unstitching you see can't be computed.
Also in Octane there is a rayipslon bias control. I donno if it exists in Corona.

regards

I usually get this issue with vray with I use 2D displacement. is world space like using 3d displacement in vray?

[romullus]

You have to assign same smoothing groups to surfaces if you don't want edges to be torn appart.

[hunter1st]

You have to assign same smoothing groups to surfaces if you don't want edges to be torn appart.

thanks ill give this a  go

[Juraj]

For true, good-looking displacement along edge, not only smoothing group (smoothing groups are btw separate vertices along separated SG islands, it's no longer single mesh, so this output is logical )
but unwrapped continuous mapping.

[hunter1st]

For true, good-looking displacement along edge, not only smoothing group (smoothing groups are btw separate vertices along separated SG islands, it's no longer single mesh, so this output is logical )
but unwrapped continuous mapping.

Hi juraj, hi romullus, My walls are already unwrapped. I tried the smoothing groups and it gave undesired affects, just as I though the shading would screw up. Seems to have fixed the problem like you said but now I have some terrible shading. Surely you shouldn't have to add a SG to get displacement working on corners? I would never usually use smoothing groups for anything except maybe with a turbo smooth for modelling.

any other suggestions? If theres no fix I'm happy to leave those edge opening in and i'll paint them out later in PS.





 

[maru]

I'm too lazy to start max so here is a mouse-to-ms-paint drawing. Try adding more edges where at the corner and then apply smooth modifier. And make these edges really close to the corner.

[hunter1st]

I'm too lazy to start max so here is a mouse-to-ms-paint drawing. Try adding more edges where at the corner and then apply smooth modifier. And make these edges really close to the corner.

thanks Maru ill give it a whirl later :)

[agentdark45]

I'm too lazy to start max so here is a mouse-to-ms-paint drawing. Try adding more edges where at the corner and then apply smooth modifier. And make these edges really close to the corner.

Interesting, I've tended to a avoid using displacement due to the undesirable effect that smoothing has on sharp cornered objects. I might have to give this a whirl...

It would still be nice to have displacement that works like vray's - apply and forget about it, no smoothing groups, geometry modification e.t.c.

[Juraj]

It would still be nice to have displacement that works like vray's - apply and forget about it, no smoothing groups, geometry modification e.t.c.

I could show you like 50 threads at CGArchitect on Vray's section where people ask the very same question about the same problem, and have been doing so for...past 10 years.
It's endless cycle where people become desperate and everyone gives them only one piece of advice.

So no. It works the very same way only with more (and very nifty) controls. Vray just also offers additional 2 modes (simple SubD and excellent 2D Texture space disp). Same protocol, people just don't know how to displace in general or
don't understand how their geometry behaves in render time. There is the option to force "continual edges" but it's not one-click saver for all cases.


Ok, here is proper workflow : // Renderer agnostic - I use the same workflow in Vray, Maxwell, and Corona. There is no difference, it's still 3dsMax Geometry.

1: Basic wall blockout.
2:Chamfer the corners (using QuadChamfer plugin for example) // Quite bit suitable than direct SubD in this case. It's quite obvious you can't smooth a cube visually ?
[ and on side note, chamfer everything everywhere, for the rest of your life ]]
3:Now you apply single smooth group if there wasn't.
4:You can directly unwrap, or apply box mapping for easier proportions, and then unwrap so it wraps continually around the chamfered corners.
[ to make this step take literally few seconds, unwrap by the spline the chamfered wall now follows horizontally ]
5:Now you can safely displace the walls for visully the best result.


There are possible workaround and dirty ways:

Invert the disp map and use negative displacement: Your geo will displace against each other. No black open edges.

[hunter1st]

It would still be nice to have displacement that works like vray's - apply and forget about it, no smoothing groups, geometry modification e.t.c.

I could show you like 50 threads at CGArchitect on Vray's section where people ask the very same question about the same problem, and have been doing so for...past 10 years.
It's endless cycle where people become desperate and forget to use logic and their brain.

So no. It works the very same way only with more (and very nifty) controls. Vray just also offers additional 2 modes (simple SubD and excellent 2D Texture space disp). Same protocol, people just don't know how to displace in general or
don't understand how their geometry behaves in render time. There is the option to force "continual edges" but it's not one-click saver for all cases.


Ok, here is proper workflow : // Renderer agnostic - I use the same workflow in Vray, Maxwell, and Corona. There is no difference, it's still 3dsMax Geometry.

1: Basic wall blockout.
2:Chamfer the corners (using QuadChamfer plugin for example) // Quite bit suitable than direct SubD in this case. It's quite obvious you can't smooth a cube visually ?
[ and on side note, chamfer everything everywhere, for the rest of your life ]]
3:Now you apply single smooth group if there wasn't.
4:You can directly unwrap, or apply box mapping for easier proportions, and then unwrapp so it wraps continually around the chamferred corners.
5:Now you can safely displace the walls for visully the best result.


There are possible workaround and dirty ways:

Invert the disp map and use negative displacement: Your geo will displace against each other. No black open edges.

This is basically the approach i did yesterday. I tired chamfered edges but it gave me even more holes even with a smoothing group. Plus I don't really want rounded edges on my sharp bricks. I'll try adding in some support edges and see what happens. Maybe my wall doesn't have enough divisions but it works fine with vray.

Ill repost later tonight.

[Juraj]

Chamfer doesn't need a radius, it can add support loops only. All very easy with QuadChamfer plugin.

Did you unwraped it correctly ? After chamfering ? Continuous mapping ? Because there is no reason why it wouldn't work then, but it won't if these steps are misaligned,
because each piece of geo is displaced by different piece of map.

[agentdark45]

It would still be nice to have displacement that works like vray's - apply and forget about it, no smoothing groups, geometry modification e.t.c.

I could show you like 50 threads at CGArchitect on Vray's section where people ask the very same question about the same problem, and have been doing so for...past 10 years.
It's endless cycle where people become desperate and everyone gives them only one piece of advice.

So no. It works the very same way only with more (and very nifty) controls. Vray just also offers additional 2 modes (simple SubD and excellent 2D Texture space disp). Same protocol, people just don't know how to displace in general or
don't understand how their geometry behaves in render time. There is the option to force "continual edges" but it's not one-click saver for all cases.


Ok, here is proper workflow : // Renderer agnostic - I use the same workflow in Vray, Maxwell, and Corona. There is no difference, it's still 3dsMax Geometry.

1: Basic wall blockout.
2:Chamfer the corners (using QuadChamfer plugin for example) // Quite bit suitable than direct SubD in this case. It's quite obvious you can't smooth a cube visually ?
[ and on side note, chamfer everything everywhere, for the rest of your life ]]
3:Now you apply single smooth group if there wasn't.
4:You can directly unwrap, or apply box mapping for easier proportions, and then unwrap so it wraps continually around the chamfered corners.
[ to make this step take literally few seconds, unwrap by the spline the chamfered wall now follows horizontally ]
5:Now you can safely displace the walls for visully the best result.


There are possible workaround and dirty ways:

Invert the disp map and use negative displacement: Your geo will displace against each other. No black open edges.

Awesome, thanks for taking the time to post those steps. That will really come in handy!

[hunter1st]

Chamfer doesn't need a radius, it can add support loops only. All very easy with QuadChamfer plugin.

Did you unwraped it correctly ? After chamfering ? Continuous mapping ? Because there is no reason why it wouldn't work then, but it won't if these steps are misaligned,
because each piece of geo is displaced by different piece of map.

hey juraj. I've managed to sort it. thanks for the tips. really impressed with the render times. All it needed was some supporting edges.

heres a couple of WIPS