arcball

[unpossible]

Hi. I quite like this, having removed the ppsm shader call to get it to work on my laptop - would be nice if it dealt with this more gracefully..

Anyway, I noticed the camera mouse delta update code suffers from gimball lock (though it's all quaternion based.. I thought it would be ok).. so I've implemented an arcball-like solution on top of what's there. It's only a couple of methods on the camera class.. seems to work ok.. would you like it?

I've got it running inside a opentk GLControl, which was also a little fiddly. Might be nice to sort out that and include a demo..

[HoneyHazard]

Yes, the pssm shader is a laptop killer. Yes, the failures should be handled more gracefully and I will try to address this soon.

When talking about the camera, are you talking about the camera in the master branch or particle-system branch? The one in the particle-system branch is likely to succeeed the camera in the main branch.
But it still is a quick dirty hack to get WavefrontOBJViewer to become a more flexible test bench. I would absolutely love to see a better solution.

David (https://github.com/jeske) would be the guy to talk to if you'd like to include a demo with SimpleScene.

[jeske]

The current third person camera doesn't have "gimbal lock" per-say .. it's designed to always maintain Y-up by design. This produces a camera locking effect at the top and bottom of rotation which might feel like, but is not technically gimbal lock.

I think an arcball camera option would be great. At some level we need to decide how to switch between camera modes. I like the idea of merging multiple modes into a single camera class and letting you switch between them. Is your code like this? An additional mode? Or does it replace the existing mode? Either way... send me a pull request, and I'll get it integrated into an "arcball mode" of the camera, alongside the existing functionality.

[unpossible]

Sorry, thanks for the rapid response; I see your point. Arcball seems to be only useful within close range of something, preferably ball-shaped, otherwise things get odd. I'm back to using the delta proc that's there. I like the Up and Right stuff; very easy to move the camera around. I do have a test winforms app with a "UseArcball" checkbox, I could try the pull request thing, not done it here before.
On another note, the ObjLoader was failing for me with bigger models. I thought it might be a type thing, and upped some of the indexes to Int32 from Int16 (eg the Face struct), but it ended up hanging :( Any chance you're looking at bigger models? Works fine for blender output of smaller stuff; thanks very much.. although, hmm, why isn't it in the lib, rather than a project outside it?

re: branches; it would merge or manually move easily, it's only 3 additional methods. I've only looked at the main branch.

[jeske]

Yes, it turns out it's a "feature" of the current "Turntable" style camera that the horizontal rotation axis is always perpendicular to world-up. WIthout it, in just a few mouse-rotations, the camera orientation will be completely unglued from any reference axis, which is usually not desired. That said, it's easy enough to make alternate camera rotations models.

That said, I do have some ideas about how I want to change the camera classes to make it easier to switch camera-navigation models for the same camera object. Hopefully it'll get to that soon.

The wavefront-obj loader (like other Util components) is not and should not be dependent on anything in simplescene. It is in a separate subproject to make sure this remains the case.

As for trouble with larger models, I'll take a look. Yes, the indicies should probably be int32 at least. There are also some unimplemented features, such as line continuations, which a larger file might be making use of. If you have an example model you can share, email me (davidj at gmail dot com).