sch1

I have been playing with Zephyr, Meshroom and SideFXLab's AliceVision plugin. I would also like to reconstruct the cameras such that when I feed in the images as background, I get an exact match to the reconstructed 3d model/scene.

My understanding is Meshroom/AliceVision may re-order the camera/path based on the matching, and not necessarily the order they were input. So you'll probably want to use the original image order to build the points, but use the image name to find out the corresponding camera position from the meshroom output.

With the latest AV Photogrammetry node, the third output seems to be the alembic cameras. You can unpack to get at the local coordinate systems, or grab the primitive transform intrinsic attribute. What I'm finding is that Meshroom/AliceVision tend to give vertically inverted outputs even though the rgb axis in the camera output has green pointing up (I assume rgb means xyz). Maybe it's just a left vs right hand thing?

Also this known issue about Alembic import has been around for a few years. Has it been resolved with the latest meshroom-2020.0.1/AliceVision 2.3.0?

Known Issues

Error reporting is relatively light right now
Cameras currently cannot be extracted from the scan due to a bug in Alembic import in Houdini. This should soon be resolved.

Most of the time, the flipbook images are drawn as gl wireframes. I don't think they look so great scaled. I would much prefer to be able to specify an exact pixel dimension before the flipbook images are generated. Is there a way for this to be specified with the flipbook interface? I suppose I can create a new viewport with the pixel dimension I want and flipbook using that.

The objectscene output driver used to render out open gl images (wireframe, shaded, hiddenline, etc) with the ability to set exact pixel dimension and renders offscreen. I take it now it will take multiple renderer with a pull down list, but the list is empty. Are there gl ones that I can register to the list?

Chyuan

With the “Interactive Update” off, if I put down a node during playback, its parameters are not updated (–). When I stop the playback, I would expect the parameters to be updated. But they are blank, until I start changing them or click on the label, individually. And let's say I click on the label of one of the parameters so the value shows up, then create another node of the same type. The only parameter with values would be the one I just clicked in the old node, with everything else blank. Is this how it should work? Again, I would have expected an update to fill in the values of the parameters when the playback has stopped. This is houdini running on Linux, but I've seen it on a different platform as well.

Chyuan