I have a vertex offset question at UE4 material.
I want to deform a static mesh cylinder like a spline. I want to deform through a material.
I have spline data - start point, start tangent and end point, end tangent.
Not an unreal expert here, no idea how to do specific things exactly but this sounds like instead of offsetting your calculated spline position by the original actors position (because that only handles position, not rotation or scaling) you need to do a full matrix transformation of you calculated spline points and then connect the output of that transform node into an absolute world position socket.
You are feeding in Local space parameters, so the spline algorithm is giving you local space coordinate outputs, hence why you have to pump in the object scale and position.
Instead of applying the transformations separately, feed it through a transform position node set to source = local space and target = world space to apply all the transforms at once. (including rotation)
This will give you a world space location of that spline point from which you can subtract your original world space to get the offset you need to get a vertex from it’s original position to it’s new position on the spline.
I can calculate the direction at each spline point (blue arrow) after the deformation in local space.
I have information about the original vertex directions (red and yellow arrows).
How can I recalculate new vertex directions?