VRay "Extrude" idea

[snivlem]

Hi,

I am pretty impressed by VRayClipper's abillity to "solidify" objects when they are cut. ie make them look as if they are solid. I suppose it is using the same tech as VRayDistance in that it uses render time booleans somehow. If this is the case I had an idea to implement this in another area. I know it wouldn't be a 1:1 translation of code but bear with me!

Basically if we had this object.



There are several tricky ways to make it appear thick without V-Ray including modelling of even 3rd party solutions with VRayPattern.

What I propose is that there is a V-Ray attribute that is able to thicken objects such as the one attached in a way that makes it appear solid. It would be kind of like a render time boolean but being able to read the opacity of a material. Is this possible and am I explaining myself properly?

[cheerioboy]

why not vray displacement with the water level threshold?

[snivlem]

It becomes too heavy with displacement especially when you are talking 1000's of holes and resolution required to make them smooth.

[ivaylo.ivanov]

One way to do this is using env fog. The performance is not that great, but if this is something useful, we may work on it:

env_fog.zip

It's using a python script to enable the "solid mode" option which is currently exposed only for Maya fluids.

[snivlem]

Thanks Ivaylo. I'll have a play around with that scene .

[Algehov]

why not vray displacement with the water level threshold?

Wouldnt that also remove the backside? So seeing it from behind it would look wierd. Unless you duplicate it and turn off displacement on the copy I guess.

[cheerioboy]

Wouldnt that also remove the backside? So seeing it from behind it would look wierd. Unless you duplicate it and turn off displacement on the copy I guess.

Yeah the trick is to duplicate the geometry and flip the normals, then displace the other direction. I've used this for a project and it worked well using 2d displacement.

[Algehov]

Yeah the trick is to duplicate the geometry and flip the normals, then displace the other direction. I've used this for a project and it worked well using 2d displacement.

In that case I find snivlem's idea very nice and handy. Makes it way easier to change and handle many geometries with this at once. Rather than having the backside geometry to worry about aswell.
Its a nice idea, and perhaps a solution similar to doing the process you described, but on 1 mesh as a renderable thickness/extrude would do the trick, and be easy enough to implement?
Rather than the env fog solution which does indeed sound abit overkill/slow.

[thomaskc]

Is there no "shell modifier" in Maya?

didn't they introduce that in 2015 or 2016?

Just like in max, why can't you use an opacity texture with a "shell" and done? or am I missing something here?

[snivlem]

There is a "thickness" attribute for the extrude node in Maya but it is pretty unreliable and you would have to boolean or model many holes in the first place which gets complicated if you are doing more advanced surfaces than just this example. Or even if one were to do more advanced shapes than just circles.

opacity texture with a "shell" and done?

AFAIK this isn't possible with Maya. From the sounds of it though it is the exact same thing as my idea, so glad it is already possible albeit in another package!

[super gnu]

the "shell" modifier in max just takes a single sided piece of geometry and gives it thickness. you still need any holes modelled. it has no way to use textures for anything.

id imagine this is something you could potentially do with an isosurface, but id also imagine it would be heavier than displacement or a pure model.


in max there is a plugin called "vraypattern" that you can use like displacement, but it repeats and deforms a specified geometry tile over a surface whlie using very little memory. you model a single piece with a single hole, and specify the surface to apply to.

-only works with repeating tiled patterns though (some randomness /control allowed) , and since buying it, ive used it approximately 0 times.


http://rendering.ru/ru_en/vraypattern.html

[super gnu]

ah.. haha.. its now available for maya

http://rendering.ru/ru_en/vraypattern-maya.html

[snivlem]

Yes, this is good tech but the problem is there is sometimes not quick resolutions with bugfixes or builds with new versions of Maya.

Apart from that it's actually really decent for grass fields (using a projection map to break up reptition) and a myriad of other things like chain mesh etc... In fact I can't work out why this isn't in V-Ray to be honest.