Photogrammetry

[Kadri]

By the way guys and girls.

I had something since a long while in my mind but the ongoing animation render and a little laziness prevented me to test it.

As Jordan is complaining about texturing Terragen exported objects...
It is certain that we need really better texture export for Terragen.

Did anyone tried photogrammetry software using Terragen rendered images?

We could easily render the needed 360 degree and what not images to get an object that does have the texture on it with UV.
Contrary to outdoor photos having to deal with this or that bad lighting, that would be very easy to do in Terragen.

Would be great if anyone would test this. Downside could be render time.
But without shadows and atmo (ideal for photogrammetry ) they should render actually much much faster then normal renders.

I don't know if this would be actually practical as this is a different workflow with another software ( photogrammetry) regarding time etc.
The downside might be obj size limit. Upside a really working UV textured object.

But just for fun it sounds nice to my ear

[Dune]

What kind of object are you thinking about? And how would you have to set up the camera to capture that? Inside the object? You wouldn't want any holes in the object.

[Kadri]

What kind of object are you thinking about? And how would you have to set up the camera to capture that? Inside the object? You wouldn't want any holes in the object.

Our main problem is landscapes rocks etc. But you can make everything Terragen exports as objects.

Camera is mostly 360 degree kinda photos step photos-renders taken from a certain different angle then before.

Depends on the object, images and photogrammetry software how many steps of photos-renders would be enough.
Holes work too. But the quality depends on all of those things together.
I don't know how inside would work but the principle is the same.
You might remember this:
https://planetside.co.uk/forums/index.php/topic,18805.msg183042.html#msg183042
That was a real life object of course.

[WAS]

Turn table viewing to create an object mesh. It should be doable, and be able to get very good results as we can make sure only the item in question is in the scene to be observed ny other software.

[Kadri]

Yes.

[WAS]

I am not too familiar with how its done but doesnt it need some sort of depthed lighting to see the objects geometry? So you end up with baked shadows?

[Kadri]

I am not too familiar with how its done but doesnt it need some sort of depthed lighting to see the objects geometry? So you end up with baked shadows?

Hmm...i can't remember Jordan.
Not sure if those are taking the shadows into account or just the changing structure or whatever.
Even if it is with shadows we could change at least the UV map.
I might try tomorrow maybe.
30 hours without sleep...

[WAS]

Oh yeah I'd get some sleep. I'm trying to find software that would be good to use but so far they all toggle to CPU modes because they only use Nvidia CUDA technology. :\

[WAS]

So I found this video while looking up phones that I may pickup and it actually has good info on how you may want to setup scene in TG lighting wise. Rotating the objects themselves may be easier than a camera on rail.

[gao_jian11]

Yes, it is totally feasible. I conducted a simple test in 2019. At that time, RealityCapture BETA could be used for free for one month. I don't know if it's okay now.
I set up the camera around the rock, and then rendered an image at 5 frames intervals, and got the result in Figure 3. At that time, the shadow of the sun was not seriously considered. In short, there is a lot to do.

[Dune]

For a single rock like that, you could put it on a very small area, so you get rid of the whole planet.

Handy if you want to edit it later and reimport, but if a nice rock can be made within TG and it's good enough, I wouldn't bother.

[Kadri]

Yes, it is totally feasible. I conducted a simple test in 2019. At that time, RealityCapture BETA could be used for free for one month. I don't know if it's okay now.
I set up the camera around the rock, and then rendered an image at 5 frames intervals, and got the result in Figure 3. At that time, the shadow of the sun was not seriously considered. In short, there is a lot to do.

Nice test. Haven't tried RealityCapture.

I used 3DF Zephyr Free for my test. There are some restrictions i think but haven't looked much into it.
The object is very very low poly i got. Half Mb. I used only 800x 30 renders from only one Y high position.
All took under 1 hour or so. Rendering included. All in all a very low poly approach.
So it could be much better with different options and renders etc. as there are quite good objects around on the web.

But just using a front projection for an exported imported obj (if you need it at all of course) looks better from what i see after this test.
But there could be special uses maybe.

[Kadri]

I had a little closer look at the settings and got  this time  a 1.6 Mb obj with the same 30 renders.
Better but still very low of course. I wouldn't use this method except special needs as i said.

[Kadri]

I made a third attempt with 30 HD images.
Rendering included it took around 2 hours (depends on settings and hardware of course).

This time i got a 100 Mb obj file.
With a better preparation of the landscape, camera position, more images etc. it could be made better then this.

I used Poseray to smooth normals. But could have used higher settings.
The object comes into Terragen with different axes then 3DF Zephyr (maybe there are settings?)  so you have to change it.

[WAS]

Yeah Unless you con properly turn table tbe landscape you ate going to get poor results and possibly bad geometry info for shape

You will want to rotate the object itself with camera sitting still, and have everything off but lighting. Not even atmosphere if you can get away with it. But also a dark background helps too. 

For doing rocks, and such, you should be able to get good results if you use large unnoisy renders.