I need to remove the triangles of object facing opposite to the camera (i.e. they aren't visible). How can I directly remove them, or perhaps get their ids?
#Visible Triangles of an Object
granite stump
sleek cave
What do you mean by 'remove'? By default Three won't render any triangle that faces away from the camera; https://threejs.org/docs/#api/en/materials/Material.side
red patio
You need to make sure the order of your vertex in your faces array image are in the right order
granite stump
What do you mean by 'remove'? By default Three won't render any triangle that fa...
I want to permanently remove those faces, and export the changed model. So if I can't delete them using threejs, atleast I need the list of triangles (or ids) to be deleted. Handling UVs is a different thing.
granite stump
You need to make sure the order of your vertex in your faces array image are in ...
Yes yes, if I have ids, I need to ensure lot of order-related stuff. But how to get those backside triangles ids?
sleek cave
The most straightforward way would be to just do the math yourself — compute the triangle's normal, take the dot product with your camera facing vector, and check its sign.
granite stump
yes, I can write the code manually. but then how do I make it fast, because the triangles are in millions?
sleek cave
How fast does it need to be? The time to do the multiplies and compares should be a fraction of the time needed to actually export the triangle data.
red patio
Web workers if it's manageable. If not, shaders it is. Never did shaders for vertex computations in three thi