Make 3d extruded geometry from alpha map

[Art48]

Hi,

Right now we're doing a papercut image and our workflow looks like this:

1) Generate path in illustrator
2) Clean up and import into 3ds max
3) Extrude path a little for thickness of paper

This workflow has huge disadvantages when it comes to complex shapes. There are countless self intersections and messes like that.

Now what would be phenomenal is if we could just take an alpha map and extrude that one as real geometry. Like when you make a plane, map ana lpha of a leaf texture on it, then apply a shell modifier. Only that the resulting geometry wouldn't be an extruded plane (cuboid) but the actual shape of the leaf extruded.

Does that make sense? Is it possible? That in junction with the VRayEdgesTex as bump so we can have a little rounded edges effects would be cool. Now if there's a way to make quad geometry out of an alpha map that would be even cooler so it can be distorted and such. But I guess that is too much to ask of a render engine :P

[andy51]

Since I imagine you would need to generate the alpha map, same as you would the path in illustrator. I can image it being just as much of a mess, generating geometry from an alpha map (bitmap), even with it's anti-aliased edges, as you would a badly drawn vector path (or traced bitmap), so I don't see any advantages, compared to your current workflow,.. and then wanting VrayEdgesTex, to round said edges, of the generated extrusion, would just extenuate the problem. .

Anyway, this is a feature request for the 3D program itself and who knows someone may already have created a script to achieve such a thing, but certainly not a feature for V-Ray, it's a render engine after all, not a 3D program.

[anthonyh]

I think I read about a plugin that did that, searching...Seem to be a couple, Pictor http://www.cgpack.com/pictor-ver-2-0-0/ and Image Trace Script http://www.evvisual.com/image-tracer-2/
I dont know if either are any good or whether they work in the latest 3dsmax as I`ve never used them, they`re not free but at least fairly cheap.
anthonyh

[andy51]

I think I read about a plugin that did that, searching...Seem to be a couple, Pictor http://www.cgpack.com/pictor-ver-2-0-0/ and Image Trace Script http://www.evvisual.com/image-tracer-2/
I dont know if either are any good or whether they work in the latest 3dsmax as I`ve never used them, they`re not free but at least fairly cheap.
anthonyh

Hey that pictor looks very familiar, works with colour images and works with 2011+, though not sure how many versions above 2011 and definitely looks like it works quite well, going by the examles

Image Tracer Script works in Max 2009 to 2017 (at least) could work with 2018 and 2019, but not sure, however it only works with black and white images, colours get converted to black, but you do have a threshold setting to change that. It also has a "Smooth It" function to handle the jagged edges of bitmaps, but only working with black and white images, limits it's usefulness for those that want colours preserved. However if you want it for Alpha maps, then it's probably the one to go for.

Of course both are quite old and there may be better scripts / plugins out there. Just remember Illustrator, since you are using it, can trace bitmaps

[Art48]

The thing about tracing bitmaps in illustrator is the mess it generates. I tried it and especially on more complex objects you have to do so much cleanup that you may well model the thing yourself or trace it yourself. Intersecting and layered shapes everywhere, it just doesn't work. The scripts you linked seem interesting although they might just do the exact same thing than illustrator. I'll have a look, thanks!

[andy51]

The thing about tracing bitmaps in illustrator is the mess it generates. I tried it and especially on more complex objects you have to do so much cleanup that you may well model the thing yourself or trace it yourself. Intersecting and layered shapes everywhere, it just doesn't work. The scripts you linked seem interesting although they might just do the exact same thing than illustrator. I'll have a look, thanks!

That's my whole point.. auto trace or manual trace, first is messy, second is very time consuming.. but the thing is, asking for alpha maps to be converted into geometry, would mean Chaos Group, having to solve the same problem that those scripts and Illustrator have tried to solve (Illustrator having had many years to solve the problem), which is tracing a bitmap and producing spline shapes, which can then be extruded by a 3D Program. So I seriously doubt you wil find this becoming a feature of V-Ray any time soon.

OH and here's a little tip I picked up long ago

Just in case you've not heard about this before. When you save a vector file .ai from Illustrator, make sure it's in Illustrator 8 format, as per image. Found this little trick/tip long ago. No idea if Max in later reincarnations has improved on the .ai import, but importing anything above Illustrator 8 format, can give you problems

[Art48]

Hi,

I knew about the illustrator 8 thing, itr really doesn't make things any better, just readable at all :P.

As for Chaosgroup implementing this I thought about it as a part of the VRayDisplacementModifier maybe since it already has that water level thing implements and basically it should be able to just keep the original faces as backfaces so that the extruded stuff isnt 0 thickness anymore.

[Neilg]

You might get better results generating the .ai path in photoshop by converting a selection. it's a little smoother and less detailed, but it'll stop you from getting serious geometry issues.

[cheerioboy]

You could use an alpha map with the vraydisplacement modifier on a piece of geometry, and then use the 'water level' to clip away the unwanted parts.

[andy51]

The vraydisplacement modifiers water level , doesn't work the way Art48, seem to believe it does, it isn't tracing a path around the extruded object, at the water level, it is just clipping the displaced geometry, plus it is going to be far harder to control, even if you used it, since vraydisplacement is not visible in the viewport. Also the way displacement works, to get a really nice extruded object, from a bitmap (alpha image), you need it to be extremely high-res black and white (not grey).

Example, say you draw path in Illustrator, say it's a star shape, you import that into Max and extrude it, it has nice straight. vertical sides, just what you need... Now lets say you use vraydsplacement mod. with a so called black and white image, if it is a true black and white image, it will have very jagged edges and the extruded sides of the object, would look awful (unless they are perfectly straight in x or y and al angles are 90degrees), if however, it has anti aliased edges, then not only would they look awful, they would not be straight either, since the black part of the image, would be at the height set, then as it goes from black to white,the displacement would slope off, until it reached the white part of the image, where it would be at the ground or water level.

Simple answer is, there is no easy way to do it. Either you trace the bitmap image, either manually or automatically (with some cleanup). Some things take time, especially if you want good results. AND as I say, asking Chaos Group to implement such a feature, is basically asking them to do something, many others, including Adobe (Illustrator) and those responsible for the two scripts/plugins already mentioned. You want them to read in a black and white image, auto-trace it and then extrude said spline(s) to create a 3D object.. and get better results than you get in Illustrator

Using PIXEL images, black and white, greyscale or colour whatever and tracing them, to generate vector paths, without having to do anything but click a few buttons, will never be as good as hand tracing. Same as drawing a mask with the paintbrush in Photoshop, will never be as accurate as using the pen tool..

Have used both Photoshop and even Max to trace bitmaps myself and yes it takes time, but it's the most accurate way I know of.

[Vizioen]

You could use an alpha map with the vraydisplacement modifier on a piece of geometry, and then use the 'water level' to clip away the unwanted parts.

This works perfectly fine.