Aerial Imagery in LumenRT

Offline Benjamin Pierce over 7 years ago

I am working on a LumenRT model for a medium sized civil project. I have exported my existing surface to a Descartes Scalable Terrain Model and successfully draped an aerial image on it. However, when I export to LumenRT I get weird results.

If I simply export to LumenRT (normal model) the aerial image on the surface looks terrific, but the civil elements look terrible. Alternatively, when I export to a "large" LumenRT model, I get civil elements that look great, but the aerial image does not come in.

What can i do to make the aerial image look as good in the "large" LumenRT model as it does in the regular LumenRT model?

I am using LumenRT Version 16.01.30.66 and Microstation SS4 Version 08.11.09.832

Thanks,

-Ben

Attachments:

Regular-1.jpg: "Regular" LumenRT Model

Regular-2.jpg: "Regular" LumenRT Model

Large-1.jpg: "Large" LumenRT Model

Parents

0 Mara Manconi Thu, Jan 26 2017 4:21 AM

Hi,

what's the size or your file? greater than 2GB?

regards
Mara
Cancel
Vote Up 0 Vote Down

Sign in to reply

Verify Answer

Cancel
0 Offline Benjamin Pierce Thu, Jan 26 2017 9:03 AM in reply to Mara Manconi

The .lrt file ends up being about 0.5 GB raw from Microstation. The image that is being draped is relatively small, and is only 8 MB.

-Ben
Cancel
Vote Up 0 Vote Down

Sign in to reply

Verify Answer

Cancel
0 Mara Manconi Thu, Jan 26 2017 9:20 AM in reply to Benjamin Pierce

Hi Benjamin,

sorry I wasn't clear, I mean the whole dgn file, before export to LumenRT Connect Edition Up 1.
Because there is a know defect regarding files greater than 2GB .

if it is not the case, please sent us the file in order to test in our environment

regards
Mara
Cancel
Vote Up 0 Vote Down

Sign in to reply

Verify Answer

Cancel
0 Offline Benjamin Pierce Mon, Jan 30 2017 9:28 AM in reply to Mara Manconi

Mara,

All of the information, both in the original file and references, is only 155 MB total. I have uploaded a zip file containing the original file (Modeling_BAP.dgn), the image draped surface (pa0206_NoVoids_Descartes.dgn) and some other ancillary references to the Bentley secure upload system. Let me know if you need anything else.

Thanks,

Benjamin
Cancel
Vote Up 0 Vote Down

Sign in to reply

Verify Answer

Cancel
0 Mara Manconi Tue, Feb 14 2017 3:51 AM in reply to Benjamin Pierce

Hi Benjamin,

The full resolution aerial images are not taken across from LumenRT. Here is what happens depending on the type of terrain used:

1. If using a MicroStation Terrain Model, the aerial maps are composited into a 1K x 1K image (V8i) or 4K x 4K image (Microstation Connect Edition)
2. If using a Descartes STM (this is your case), the images are broken up into 512 x 512 or 1024 x 1024 tiles depending on the resolution of the terrain – moving closer to the terrain with the camera will generate larger image tiles.
3. If using a RealityMesh for the terrain, these are tiled at 512 x 512

I hope this explains

regards
Mara
Cancel
Vote Up 0 Vote Down

Sign in to reply

Verify Answer

Reject Answer

Cancel
0 Offline Max Voigt Tue, Feb 14 2017 4:11 AM in reply to Mara Manconi
Hi Mara,

What's not clear from your explanation is the actual size of the tiles being compared.

If I had a 1km x 1km draped mesh, with the draped image being 8000pix x 8000pix, are you saying that V8i would resample the single image down to 1000pix x 1000pix - or create 8 tiles of 1000pix x 1000pix each?

Similarly, would CE more efficiently create two tiles of 4000pix x 4000pix?

Essentially, which is the best method to create the highest resolution? From your notes it looks like;

Best = Connect Edition draped mesh
Next best = V8i mesh draped mesh
No too good = Descartes STM & Reality mesh.

Also, what is the purpose of "large model LumenRT export" relative to the standard export? Does it control resolution output, or fidelity of imported geometry?

Max
Cancel
Vote Up 0 Vote Down

Sign in to reply

Verify Answer

Cancel
0 Offline Benjamin Pierce Tue, Feb 14 2017 9:16 AM in reply to Mara Manconi

Mara,

I am still somewhat confused.

Why does small model export versus large model export handle the exact same draped image differently? Why is the small model export properly shown with bright colored aerial image pixels but the large model export black? It looks like a software bug.

Are you suggesting that if I split up a high resolution image into a bunch of smaller image tiles, LumenRT will successfully show the drape at full resolution in either large or small model export?

-Ben
Cancel
Vote Up 0 Vote Down

Sign in to reply

Verify Answer

Cancel

Reply

0 Offline Benjamin Pierce Tue, Feb 14 2017 9:16 AM in reply to Mara Manconi

Mara,

I am still somewhat confused.

Why does small model export versus large model export handle the exact same draped image differently? Why is the small model export properly shown with bright colored aerial image pixels but the large model export black? It looks like a software bug.

Are you suggesting that if I split up a high resolution image into a bunch of smaller image tiles, LumenRT will successfully show the drape at full resolution in either large or small model export?

-Ben
Cancel
Vote Up 0 Vote Down

Sign in to reply

Verify Answer

Cancel

Children

0 Offline David Burdick Tue, Feb 14 2017 11:25 AM in reply to Benjamin Pierce
LumenRT Large Model Export is a V8i-only export facility to accommodate 32-bit operation on large models to prevent crashing. It basically does a 2 stage export so it's slower but more reliable than standard export. It has no bearing on the output resolution of image/aerial maps.
Cancel
Vote Up 0 Vote Down

Sign in to reply

Verify Answer

Cancel
0 Offline Benjamin Pierce Tue, Feb 14 2017 1:44 PM in reply to David Burdick

David,

That would stand to reason that if separate exports to small and large models from the same file completed successfully, the output of both exports would be the same. As shown in the images above, the aerial images and model objects come in differently. The large model export does a better job with the 3d shapes, but shows aerial as black whereas the small model export shows the aerial image correctly but makes the objects render improperly if you zoom in too close.

What do you think could be the cause of this?

Thanks,
Ben
Cancel
Vote Up 0 Vote Down

Sign in to reply

Verify Answer

Cancel
0 Offline David Burdick Tue, Feb 14 2017 1:48 PM in reply to Benjamin Pierce
Hi Ben,

It is probably a bug on the large model export facility in V8i causing this. Can you send me a PZIP of the file and the associated images and I will get someone to look at this. Send me a link to the file to david.burdick@bentley.com
Cancel
Vote Up 0 Vote Down

Sign in to reply

Verify Answer

Cancel