Problem with Surface using Displacement in CineRender

[Anonymous]

I am having a problem with a surface I have created for a corrugated roof where the displacement shows correctly on some parts of the roof element, but not on others. There are distinct lines between the good and bad parts which run between the nodes of the roof. I'm pretty sure it is related to the surface settings as opposed to the render settings, because I have tried it with the stock ArchiCAD scenes (Outdoor Daylight Final, for example) and get the same result.

So I'm just wondering if anyone else has had a similar problem, or if they can suggest what settings I could change to fix the issue. I think it must be a bug, but hopefully there is a work around as well.

Original perspective:



Just the roof element showing the same problem:



Eave modifications removed showing how the problem changes with the roof:



Close up of the variations in the surface:



I have shared the surface to BIMcomponents but it hasn't showed up yet. I will upload it once I see it on there, but in the mean time you might find it by searching "colorbond roof".

Thanks

Ben

[Aaron Bourgoin]

this is just a guess. ArchiCAD roof planes now have nomenclature for individual edges. Try highlighting a piece of problem roof and inspect the edges to make sure that the ridge self-identifies as a ridge, a hip a hip, etc.

Surfacing tools like Cadimage coverings rely on the edge types to do what they do and so it might also be the case that the texture mapping also follows a ruleset based on the edge names.

also check that you have a common 3D surface orientation point for all the roofs.

[Anonymous]

Thanks for the suggestion Aaron, but I checked all the edges and they were set correctly. Originally I had the whole roof as a single element, but I had to change it to individual roof planes so that I could set the surface orientation (you can't set the 3D texture origin on a multi plane roof apparently), and so in changing that it must have kept the edge types. But I did try changing the cut-out section of the eave from "eaves" to "undefined" but it didn't make any difference. But that answers your other suggestion, that I have set a common point for the 3D textures/surfaces.

So does anyone else have any suggestions? I am still waiting for the surface to show up on BIMcomponents...

[Barry Kelly]

I have been experimenting with this myself and haven't found the perfect settings.
There are so many other settings to sort out and I think the geometry of the roof has an effect as this will determine the triangulation of the surfaces.

The main culprit I have found is the 'Subdivision Level' in the displacement settings of the surface.
Increasing the number seems to refine the effect but also slows down the render process.

Barry.

[Anonymous]

Thanks Barry - I'm glad I'm not the only one who's having this problem. I just tried increasing the subdivision level (and I think you're right about that - I had to play around with this a bit when I was setting up the surface) from 9 to 10, but my computer ran out of memory and started playing up. Previously the render only took an hour or so. I guess I will just have to live with it for now.

[Anonymous]

Ben,
I would probably just increase the modelling detail (use roof surfaced to place corrugated sheeting, ridge caps etc) rather than displacement as I havd found that using displacement dramatically increases render times
Scott

[Anonymous]

Thanks for the tip Scott. That is something I've thought about and tried before, and I think I had problems with the model being too detailed and therefore slow, and also the elevations not being as neat as with simple cover fills. But I may have gone about it the wrong way, and I'm not against the idea. I will probably get Cadimage Coverings sometime in the future to do that sort of detailing for me.

Anyway, the displacement problem is now being looked at by Graphisoft, so we'll see what happens. And my surface finally got added to BIMcomponents, but I don't think there's any need to upload it here now.

[Barry Kelly]

benanna88 wrote:
Anyway, the displacement problem is now being looked at by Graphisoft, so we'll see what happens.

If you get a solution be sure to let us know please.

Barry.

[Anonymous]

Will do.

[Anonymous]

I have heard back from Graphisoft with a solution, which after some testing I have found does improve the renders, but doesn't solve the issue completely. I have sent back my latest tests, and it sounds like they will keep working on it, but in the mean time, simply try turning off Sub-Polygon Displacement in the render settings under Detailed Settings > Options > General Options.

Actually, having just examined my tests a little closer, I've realised that doing this just turns off the displacement effect completely...