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Mattoo
06-19-2008, 04:21 PM
Hello, I've been using DP Kit quite extensively here but could really use some help on this one.
I'm trying to use the Curvatures node to highlight bevelled edges for use as alpha masks for features such as weathering and chipped paintwork. Normally weight maps would suffice but I was really looking for a shader based solution as a time saver.
Curvatures works great for this on curvy surfaces, but proper hard surface models don't fair so well.
I've tried using the DP Blur filter, but that doesn't appear to work with Curvatures. :(

As you can see, 'Curvatures' is nicely highlighting the bevelled edges, but I am unable to create a soft blend into the flatter areas.

Anyone got any ideas or am I stuck with a nasty weight mapping task?

http://www.matt-painter.co.uk/fun/curvatures.jpg

dpont
06-20-2008, 02:23 AM
Curvatures node could not be affected by the Blur Filter node,
because Curvatures is geometry related and Blur works only
on spot position, but this spot belongs still to the same polygon.
Even with a Gradient node, you couldn't achieve this
effect because polygons have the same curvature.

Edge node could do a fuzzed colored edge and fake the
rounded edge too, on a simple box, but if you need a
real rounded box, I think that a node tree will be
more complicated than a simple gradient image
with an UV map.

Denis.

Mattoo
06-20-2008, 03:23 AM
Edge node could do a fuzzed colored edge and fake the
rounded edge too, on a simple box, but if you need a
real rounded box, I think that a node tree will be
more complicated than a simple gradient image
with an UV map.

Denis.


Hi Denis,

Thanks for the response. I was looking for a shader based approach due to the amount of geometry I have like this to texture. In simple terms I was looking for something that does the inverse of EE_Grit - something that highlights the exposed edges with a falloff, just as EE_grit does with recesses.

At the moment I've been using a combination of AO and Curvatures to do this, but certain situations, such as this cube, fail.

dpont
06-20-2008, 04:22 AM
With a simpler geometry (not rounded) Edge node
works like that, I think that it is convincing at a reasonable
distance for the camera,

60033 60032

Denis.

Mattoo
06-20-2008, 05:35 AM
With a simpler geometry (not rounded) Edge node
works like that, I think that it is convincing at a reasonable
distance for the camera,

60033 60032

Denis.


Yeah, that's true, and we looked at the Edge node first, but sadly these models are very highpoly with every edge bevelled - but it doesn't work with bevelled edges and suffers the same fate as Curvatures.

dpont
06-20-2008, 06:45 AM
Your question is bit perverse, since you showed a simple rounded box,
and then you are speaking of a highpoly model, how about its
topology?

I think reducing a highpoly to get only one edge instead of
roundish poly could be possible, or like I said before a complex
nodal tree but should draw fuzzy edge, only if your model
(like the box) has only horizontal and vertical sides,
since the edge polys have same smoothing angle and
curvature, the last thing should be to get the local normal
make it positive vector, find the maximum (horiz or vert)
component, power it to control the fuzz and use it
as opacity in a Mixer node,

60035

Denis.

Mattoo
06-20-2008, 07:08 AM
Thanks for your time Denis. Sadly reducing the geometry to take advantage of your Edge node is not an option and the cube isn't the best example.

I'll try and put together a better example later on.

Mattoo
06-20-2008, 07:49 AM
Here's a good example of the kind of objects that are in need of texturing. As you might imagine, applying weight maps and UV maps to this sort of thing is very hard - I have done it that way in the past. But what I'm really looking for is a much quicker, procedural way of creating the "dry brushing" effect on all the exposed edges.

EE_Grit works just fine for the crevices, but the inverse of EE_Grit is needed for the warn and chipped paintwork for all the sticky-out bits.

I hope this is a better example? (yes, I know this is a photo, but I can't show any of the actual work)

dpont
06-20-2008, 09:07 AM
Yes...
It is more a paint task and you could not find a shader for
all situations, if you just need to texture effect for the rounded edge,
why not baking the curvature or edge node effect and bluring the
resulted image before using it ?

Denis.

Weepul
06-20-2008, 03:39 PM
EE_Grit works just fine for the crevices, but the inverse of EE_Grit is needed for the warn and chipped paintwork for all the sticky-out bits

Funny you should say that. Enter a negative sensitivity in ee_GritNode and seeif that does what you need...

Using dpont's Replace Spot node might help that setup, but I wouldn't know, since that node isn't available for Mac AFAIK.

Mattoo
06-20-2008, 05:21 PM
Funny you should say that. Enter a negative sensitivity in ee_GritNode and seeif that does what you need...

Using dpont's Replace Spot node might help that setup, but I wouldn't know, since that node isn't available for Mac AFAIK.

AAAAHHH!!!! Holy crap! That works! Why didn't I think of that?!?! Answers on a postcard to:

Mr A N Idiot
132 Obvious Terrace
New Doltsville
Stupidland

I'll have to try it out properly when I get back to the office, but it certainly works well on this bevelled cube!

Thanks Weepul, I owe you a pint! (or twelve) :thumbsup:

Weepul
06-20-2008, 07:00 PM
No problem. :) Before you celebrate too heartily though, when I tried it, it kept giving me faint traces of polygon edges, which is why Replace Spot might help (to offset the ray start position)...

Mattoo
06-20-2008, 07:39 PM
No problem. :) Before you celebrate too heartily though, when I tried it, it kept giving me faint traces of polygon edges, which is why Replace Spot might help (to offset the ray start position)...

Yeah, I got that too, but I goofed with the gamma a bit and it went away. However, I might have to bug you about that if it does become a problem... :hey:

Mattoo
06-23-2008, 09:47 AM
No problem. :) Before you celebrate too heartily though, when I tried it, it kept giving me faint traces of polygon edges, which is why Replace Spot might help (to offset the ray start position)...



OK, I give up. How might one use Denis' Replace Spot tool to get rid of the wireframe effect? :help:

The Replace Spot tool is part of Denis' Image Filter nodes, it hurts my brain to imagine how that might work.

Weepul
06-24-2008, 04:21 PM
Well, I'd be hard pressed to help you with that one, since I can't try it for myself (no Mac version)... If it works like I think it works, it could be used to help, but I'd really be hesitant to try explaining how without being able to use it hands-on. :(

Mattoo
06-25-2008, 12:36 AM
awww....crap. Thanks anyway.

Weepul
06-26-2008, 04:12 PM
I really wish I could help with that, in part because it means I would have a version of Replace Spot I could use/play with... ;)

As it stands, the best thing I could recommend now is to bake it to a UV and then process it a bit in Photoshop (or your image editor of choice) to get rid of the fine lines.

Mattoo
06-26-2008, 04:53 PM
To be honest it would probably be quicker just to paint vertex maps... which is probably what I'll end up doing. I'd normally be more than happy to do it if it were for a single object, but I have a LOT of tanky things to do.

I was really hoping for a nice quick solution and EE_grit with minus degrees works really well... really REALLY well! If it wasn't for those pesky wireframes! >:(

Weepul
06-28-2008, 07:36 PM
I can't test this - this is entirely a mock-up in Photoshop - but try this and tell me if it works at all...

Mattoo
06-30-2008, 02:23 PM
I can't test this - this is entirely a mock-up in Photoshop - but try this and tell me if it works at all...


Weepul, I could kiss you! A 0.01% scale isn't enough, but if I crank that up to about 0.5% it works a charm! I'm gonna have to try it tomorrow at work but a few error prone examples here really look great!

So, I think you're good for a few pints and a kiss. :hey:

For what it's worth, this is great for creating automatic masks for paint chips, especially combined with an AO shader to 'protect' the inner areas from weathering. :lightwave

Weepul
07-01-2008, 01:35 AM
Thanks! But I'd settle for some pics of the results, if you can show them. :D

I also wonder if/when I put up a portfolio site, whether I should quote that line of yours. ;D