@yorik said:
...One thing i started experimenting with is to derive a 2d view directly from the 3d view, but it is still not very stable...
But it is different thing at all. never was the same and has extra steps. Who developing opencascade?
So basically the only real way i see for big speed gain is to get rid or bypass the OCC algo
I'm a bit more optimistic than that. We're running into the same performance issues https://github.com/IfcOpenShell/IfcOpenShell/issues/1153
Scattered throughout the ifcopenshell github thread there are lot's of things I'd still like to try for performance that are somewhat specific to our domain. For example:
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Project identical geometries with the same orientation wrt view, only once and compose in SVG
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Hiding small elements by large elements (slabs / facade elements) in 2D
@yorik Wonder any relevance between the discussion here about IFCopenshell and the Draft-Shape2dView workflow discussion in your last Sept blog https://yorik.uncreated.net/blog/2021-020-freecad-september ?
Thanks.
@paullee said:
@yorik Wonder any relevance between the discussion here about IFCopenshell and the Draft-Shape2dView workflow discussion in your last Sept blog https://yorik.uncreated.net/blog/2021-020-freecad-september ?
Yes, I was going to mention that too...
Basically we went further in bypassing the HLR step. What I'm doing more and more in FreeCAD is not put any 3D furniture in the model, but instead place furniture directly as 2D elements. Plus, we have the opportunity to use BRep geometry for sanitary appliances, which reduces greatly the problem (you can make a basin with 2 or 3 faces only).
It is somehow a workaround, but at least the user is still in control of the whole process, can turn things on/off inbetween, etc. And the simple fact of breaking the whole process into different phases (HLR first, building the SVG next) is interesting, only that has the effect to cut the overall rendering times in half (half the operations you do only require one of the steps to be ran again)
With these things, at leas for a small-scale project (a house, for ex), the rendering speed is now pretty good, enough for "real work", let's say. I'm working on a 8-appartment building too, then it's a bit annoying already, you need to turn some stuff off when working, but it's doable.
The "coin-based" solution we explored some months ago is not very reliable either, and doesn't give such a huge speed gain either.
Surprisingly, in FreeCAD, a step that takes time too is have the Qt graphics engine render the SVG... For a small one it's fast, but as it gets more complex, the rendering times goes up exponentially. But that might also be something easier to optimize.
I also think more and more like @aothms , what the "big boys" out there do is basically no different, they cache, they sort, they do stuff in the background, they cut the process into chunks...
Cool stuff man,
Here is my attempt of trying to model my own house from a Point Cloud using the BlenderBIM add-on.
I only use IFC as the main source (roundtripping). It's a painful process. haha.
