Vector-like bitmap for fine displacement

[tricky]

I have a situation where I am modelling 10mm shadow gaps in a large concrete ceiling. The grid that they follow is not regular.

The most accurate way to achieve this is to actually model 10mm joints and cut them out of the ceiling slab.

However, and alternative, and perhaps more powerful approach would be to generate some kind of vector-like graphic (something like Adobe Illustrator would produce), or failing that, a very large, high resolution bitmap image file which could be used to displace the clean geometry at render time using vray displacement.

My experience with displacement, though patchy, is growing, but I believe there are limitations with using very large bitmaps. Vector-based graphics would be better as then even if I render the final image at 10k resolution, the displacement vector map will still hold up to scrutiny. Likewise, rendering smaller test renders at 1k resolution wouldn't slow down as it wouldn't be using huge bitmap textures to derive the displacement.

At the moment, I will stick to modelling the joints, but using a vector-graphic based approach would be far more powerful and flexible if the grid changes - ie I would only need to re-paint the vector map rather than remodel the ceiling.

Does this exist?
If not, is something like this possible?

[tricky]

A further idea which could be just as powerful, or even more so, would be to use simple lines drawn in Max (or imported from your Cad program) to create a negative indent over a surface. Does that make sense?

Example:
Sometimes, for joint lines on a large building, we draw polylines in AutoCAD and give these a thickness - say 10mm - in Max. This simulates the joints of a building. However, it falls apart when you get close to a joint because you will see that the joint sticks out proud from the facade cladding. In reality, the joint should be a recessed joint in the cladding.
If we could somehow use these splines to drive the displacement on the geometry, that would be really powerful.

[3DMK]

Not sure if vector lines can be done as I am not a coder...
....but I'm sure you could remodel the joints just as fast as you could re-draw the vector lines in illustrator so I'm not sure you would get any benifit out of it for something as simple as joint lines.
Using the edit poly is just soo fast and efficient when using the inset tool for joint lines....and the best part of doing it in geometry is that you don't end up with a massive amount of polys that displacement would need to get the same high quality result.
Also your GI calculations are not slowed down by having a huge amount of polys in a displaced mesh.
So many times I see guys write on these forums about being frustrated by trying to get the results they want out of displacement when they could have modeled it in 3D in a tenth of the time.
IMO displacement is way more valuable for organic shapes that are extremely difficult to model. Please don't think I am against displacement at all....but it's like most tools....it's not a magic fix for every situation.

Hope this helps

[tricky]

Mmmm. Not sure I'd agree with you there. In most/many cases, modelling geometry is faster, but being able to bring in an EPS file of joints straight from the AutoCAD GAs could be ideal. Ceiling grids can be another good use of this technique, especially when there are a number of offset grids at angles to each other.

We recently had a VVM project where the facade had a very intricate use of joints and panels with many differing conditions/layouts. The elevation had already been drawn in detail by the architect. If we could have ported their joint information over, it may have saved a lot of pain.

I take your point about the power of polymodelling, but there is a time and a place for all these tools. Our way of working is to model in AutoCAD and file link into Max. We can then share the responsibility between multiple modelling artists and the texturing/lighting/viepoint process can begin much earlier. It also means that when the design inevitably changes, updates to the model are straightforward and seamless. Also, the accuracy of AutoCAD and its snapping tools is precise. It can also handle the huge sets of 2D information supplied in the GAs with relative ease. However, the big downside of this way of working is that and 'edit' mode on the geometry inside of Max breaks the link with AutoCAD. This means that all modelling changes must be made in AutoCAD. However, things like joints and grids could be applied using displacement.

[3DMK]

I totally see your point now tricky

Personally I look at everything from a rendering point of view.....which can be limiting & would be a downfall working under your current production setup with multiple artist/workers.
Basically a specialist renderer only cares about themselves & making our life easier [selfish bastards aren't we...lol]
The intricacies of the render engine are my main concern so I tend to place more importance on that than what the CAD monkeys [please excuse the derogatory expresion] have to do to produce what I need in a model for a fast high quality render.
Maybe that's why I don't have many modeling friends left.....???

All the best
Jamie

[tricky]

Fair points. To be honest, we don't really specialise in one particular area individually: we all need to be able to do it all. We are therefore combination cad monkeys, picture colourers, coffee makers and table footy players!

[claude_tnt]

A further idea which could be just as powerful, or even more so, would be to use simple lines drawn in Max (or imported from your Cad program) to create a negative indent over a surface. Does that make sense?

this feature used to be in VIZ back in the vers 3 era.. then it disppeared without fanfare.... it allowed you to subtract one object from another (auto boolean) from objects upon creation...without using actually using the modifier...

davis

[flino2004]

I'd go to the modelling option...you'll probably expend more time trying to looks right with displacement than modelling the whole ceiling again if you need it.....I use skethup a lot and there is a plugin that pretty easy it can convert lines in autocad to geometry then you could substrac them from the ceiling....this plugin has many architectural features http://www.1001bit.com/index.html

Fernando