VRayEdgesTex chemfering - Workings and alternatives?

[Laserschwert]

I use VRayEdgesTex quite a lot to create easy rendertime chamfers on objects. But sometimes, with complex geometry (like CAD data), the map doesn't manage to stay free of artifacts around certain edges. Now I was wondering, are there any VRay compatible alternatives to this, that might work better?

Furthermore, how exactly does the map work under the hood when used as a bump map? Is it still just creating a two-color edge-map (like it does when used as a diffuse map) which gets used as a bump? Could the same effect be achieved by properly unwrapping the geometry, simply tracing the edges on the unwrapped geometry in Photoshop, and then using that map as a bump? Because if that's possible, we wouldn't have to rely on the map to properly find the edges (with the added bonus of being able to use variable edge widths in the map).

VRayDirt can also be used to create an edge map (when "invert normals" is used). Can this be utilized for edge chamfering in any way? (since VRayDirt can't be used as a bump, maybe by baking the edge map with it?)

[Guest]

I use the VRayEdgesTex to add highlights quite a lot and also receive external CAD data from clients. I found that VRayEdgesTex doesn't work on external CAD data until the vertices have been welded. Typically we import .SAT, convert to editable poly and select all verts and weld by 0.001. You can use the editable poly element selection to select the same faces as you would in body object mode.

Of course some times when welding artifacts appear, we usually work around this bey importing a different format.

[henning]

The prooptimizer modifier is also a good toolset for preparing CAD geometry for vrayedgestex.

[raymarcher]

Also form help:

When used as a bump map in glossy materials with Blinn or Ward BRDF, VRayEdgesTex may lead to dark edges; to avoid this, use the Phong BRDF instead.

[Laserschwert]

Regarding CAD-data I import using nPower's PowerTranslator. Problem is: Converting to EditablePoly usually messes up all smoothing groups (I guess because they work differently from EditableMesh). Also VertexWeld normally doesn't work at all, without messing up pretty much everything.

But aside from CAD-data, VRayEdgesTex sometimes has problems with self modeled geometry as well. It would be really cool if it was possible to bake VRyEdgesTex to a bitmap and clean it up that way. Unfortunately once it's put in the diffuse slot, it outlines ALL triangles of the mesh, and not just "sharp edges".

[Alan Iglesias]

I often import CAD data to 3DS Max with nPower's Translators Pro. If I need a chamfer I just add it by creating a fillet (while it is still a NURBs object) with the nPower software before rendering.

-Alan

[Laserschwert]

I often import CAD data to 3DS Max with nPower's Translators Pro. If I need a chamfer I just add it by creating a fillet (while it is still a NURBs object) with the nPower software before rendering.

-Alan

I guess this only works with Power Translator Pro, right? I only have Power Translator Basic. Furthermore very often the objects are so complex, that it would take forever to chamfer all edges manually (and strangely, although the fillet option shows up in the Pwr_EditNRB object, activating "Fillet All Edges" doesn't do a thing).

[Alan Iglesias]

I guess this only works with Power Translator Pro, right? I only have Power Translator Basic. Furthermore very often the objects are so complex, that it would take forever to chamfer all edges manually (and strangely, although the fillet option shows up in the Pwr_EditNRB object, activating "Fillet All Edges" doesn't do a thing).

Ah...understood. Fillet might be overkill for your application.

I'm not exactly sure if it can do this, but using your Translators Basic program can you beef up the rendering resolution by reducing the Rendering Aproximation/Face Chord parameter for your object? If you can do this, perhaps you can get a higher render-time tessellation that will allow the texture to do it's thing. I'm pretty sure you can bring it all the way down to .001 which should really push the topology tessellation for you. I'm not really sure if this will affect the texture or not, but you could give it a shot.

-Alan

[Laserschwert]

I think a higher tesselation might cause even more problems, because VRayEdgesTex usually creats artifacts on "difficult" edges, like edges that are too close together (as the map seems to be unable to draw its lines across several edges). And since CAD data often creates very thin and long triangles, those are very much suited for such problems. I'll give it a try though, thanks!

VRayEdgesTex still operates in the normal UVW space of a mesh, so I guess as long as there's no technique that's independent of that (like the way VRayDirt or VRayToon work), there's no real solution to that.

[Alan Iglesias]

>>I think a higher tesselation might cause even more problems...

Ah...Interesting, indeed.

Well, the only other thing I can think of is perhaps using the nPower software's ability to create topology based on quads (hopefully no long faces there!) to create geometry that might perhaps work for you.

I hope you find a way to help your situation...

-Alan

[vlado]

Actually there will be some improvements in that regard for the next service pack; hopefully it will make the VRayEdgesTex texture more usable in such cases.

Best regards,
Vlado

[vlado]

Here is an example.

V-Ray 2.30:


V-Ray 2.40:


Best regards,
Vlado

[vlado]

And two more:



Best regards,
Vlado

[Laserschwert]

Awesome! Really looking forward to that!

And since VRayEdgesTex gets some developer love, how about adding a "show only visible edges" option to the map?

[vlado]

And since VRayEdgesTex gets some developer love, how about adding a "show only visible edges" option to the map?

You mean for e.g. TurboSmooth isolines?

Best regards,
Vlado