Quick question, I remember there were issues with stencil shadows and non-closed mesh models, can anyone tell me if this is still true?

Do models need to be a closed mesh for shadows and other reasons?
TIA

It´s still necessary, at least you´ll need a closed LOD for the shadow.

Thank you, the reason I had asked was simply I had added an open-mesh model and was not getting any shadow casting problems. Obviously if I added a LOD to it, this would then become a problem.

Thankyou for your response

You didn´t have a problem with the open mesh?! But this would be great news!
The manual still says that open meshes cause these problems and mentions (closed) LODs as a possible solution.
I must say, I´m not 100% sure, if it was before or after the update, that I observed the messed up shadows. But if stencil shadows are working now with open meshes, that would be very nice!

Well 'TheBuggy' demo on our site, is open mesh, but it has no LOD's so it's possible that it only works with models with no LOD... If I get a moment I will test that theory.

Would be fantastic if it's no longer an issue, as constructing models which either include the faces inside a model or have extra polies so that they can be connected to other parts, is problematic and somewhat restrictive.

For example in a recent low-poly character we are making, the arms, legs, neck and torso parts have faces that will never be seen, yet due to the closed-mesh issue we are having to leave them in, so if this is no longer an issue we could trim out a further 30-40 tris from our model.

Fingers crossed...

The vertex count has triple the effect than the polygon count does so reducing the vertex count is more important than faces, but even freeing up faces does help with performance. I don't know, however, if there's any performance difference between a closed mesh and an open one.

well 40 tris can mean anything up to 120 extra unused vertex. Although in this case, its 1-2 vertex for each appendage, so in terms of our model its a saving of 7 vertex'

Not really a point about the performance improvement for the trim, although putting it into perspective here is an example:

What about a 3000+ poly first person view gun? Usually the faces that never face the camera would be trimmed out, but this would make it open mesh. I have gun models that are based on a 5k tri mesh, with forward facing tri's being removed, as well as any loose vertex's, leaving a 3000'ish tri model.

However if the stencil shadow is not an issue with open mesh models now, or if its only a problem when you start adding LOD's then this is still good news. I really need to test that today...add it to the 'to do list'

According to somewhat recent experiment results, the peak performance, at least on my system, is from 2000 to 5000 polygons. Given the logarithmic scales and that there was otherwise a straight line from these two points on the graph, the peak is around 3200 polygons so 3000+ is not a big deal.

If you want to test the stencil shadow thing, first, create a simple test subject (such as a cube) that has a closed mesh. If it runs without problems, then test it with another simple test subject that has an open mesh instead. If that runs without any problems, then repeat the open mesh test with LOD used instead (of course, you can use different colors or a slightly bigger/smaller shape). If that goes well, then there are no issues with stencil shadows and open meshes. However, if the LOD part fails and it works otherwise with open meshes, use my LOD system to counter this (as the engine's LOD system is too limited with little flexibility). If it only works with the closed mesh, then using stencil shadows isn't an option in that case.

Freeing up 120 unused vertices and 40 triangles will have an impact on performance, but not all that much (Try loading at 180-tri, 90-vertex model once and that's about the performance difference, supposedly adjusting for the use of another entity - it isn't much, but still, on 60 fps, it could add another 0.5 fps, and every little bit does count.). However, reducing 2000 triangles (about 700 vertices if it makes an open mesh) will have a large impact, turning 60 fps to something like 68 or so (raw estimate).

Wow!
I just made some tests with an animated model (open mesh, no LOD´s) and the stencil shadows worked, as if the mesh was closed. I used the model both as an NPC and as a player!
This did not work with the previous version

BTW: I (and the manual) mentioned LOD´s just as a possible workaround for this, if the shadows do not display properly. But now (with A6.4) it seems that the restriction is no longer there, and the manual should mention this.
Indiglow, that´s a great discovery!

That's a good find, but if I where you I'd ask confirmation from conitec before using this 'feature'. If this is not a supported feature it might be changed again in a later version making you waste alot of time..