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hypersuperduper
03-04-2018, 01:01 PM
Hi, all.

I am trying to figure out a way to taper the ends of silhouette edges dynamically. I have marked the edges that i want to taper in the image in red. basically I want the edge to become thinner as the edge ends, like an ink brush that has been lifted. Anyone have any ideas on how to approach this?
Incidence angle wont work, since by definition the incidence angle is pretty much always 90 degrees for silhouette edges. I cant use anything static like weight maps either, because these edges move around depending on the viewing angle.

140505

Any tips would be appreciated.

Chris S. (Fez)
03-04-2018, 04:04 PM
Been experimenting with something similar, so far unsuccessfully. I'd certainly be curious to see a solution. Perhaps Newtek could come up with a dynamic taper setting for the various line options.

MonroePoteet
03-04-2018, 04:57 PM
What is your target LW version?

mTp

hypersuperduper
03-05-2018, 01:25 AM
What is your target LW version?

mTp

2018.

I feel like some sort of raycast operation could be constructed to handle this, maybe.

MonroePoteet
03-05-2018, 07:26 AM
Well, here's a technique mutated by LW2018 from a fairly old-school technique in LW2015 which you might be able to adjust to your needs.

The basic technique is to get into Modeler and use Modify=>Transform=>More...=>Point Normal Move to make a secondary "shell" object around the original object. In this case, I used a 2mm offset in the Point Normal Move numeric panel.

The Silhouete Edges are enabled on the original object, and the shell object is parented to it. The shell object surface is then made 100% transparent, colored black, and in LW2015, I simply added the Edge Transparency modifier and adjusted the Opaque falloff and edge width to fade the edges.

In LW2018, the Edge Transparency modifier apparently isn't available any more (or I haven't found it), but simply loading the objects into LW2018 and turning on the Edges of the original object produces a really interesting result, although I'm not sure why the refraction on the shell object affects the edge drawing on the inner object:

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By adjusting the Refraction Index on the shell object, the detail lines can be made more or less prevalent. As I said, I don't know why the edge drawing is affected by the refraction of the shell, but I actually really like the results, and maybe you could use a similar shell object / technique to get what you want.

mTp

hypersuperduper
03-06-2018, 08:28 AM
thats a cool effect, but its not really what I am after judging from the image at least.

I had some success using the RayClosest Node. Its not perfect, but it works sort of like occlusion, so it can isolate the concave parts of the mesh dynamically, which is where most (but not all) of the tapering edges should be. The description of what RayClosest does is not very good in the manual currently so it took me a while to figure it out. They really should add some simple diagrams of what the different raycasting nodes do. I just plugged it into the surface color and messed with the values until I figured it out.
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paulhart
03-06-2018, 09:13 AM
Finally a 'work around' for this problem. Thank you for pursuing it and sharing your solution I will want to try it out later this AM when I have time. Good work and look.

Chris S. (Fez)
03-06-2018, 12:18 PM
Finally a 'work around' for this problem. Thank you for pursuing it and sharing your solution I will want to try it out later this AM when I have time. Good work and look.

Yes, thanks for posting Hyper.