Roof tiles - geometry or displacement ?

[Repenseks]

Hello all,

I am making 3D of the house with quite difficult roof, and want to look very good, at the same time to be "light" for rendering, because I have to make animation too.

I was wandering what will use less resources, geometry or displacement, or is there any better idea ?

Regards
Srdjan

[joconnell]

Well, if you can make it easily using displacment, copy the roof, put on a tesselate modifier and use the regular max displacement - once you get it to look the same as the vraydisplacement mod, collapse it to an editable mesh and you're good to go. Speed wise if you're using any render time stuff you'll get that speed hit at every single frame, with a dumb mesh object, just the once.

[Dynedain]

Displacement will be easier to work with in your viewport. Geometry will give you better results when closeup to the roof.

I've done it both ways depending on the needs of the specific project.

[Repenseks]

Hello joconnell,
unfortunately I did not get what you meaned

Hello Dynedain,
I guessed it will look nicer with geometry, in any way it will be difficult to uvw or model. I was mostly wondering what takes more juice from computer geometry or displacement?

I made roof out of many closed polys and extruded to 0. I will render now and upload.

Regards
Srdjan

[Repenseks]

Hello,

there is the image. I did not refine it yet.



Regards
Srdjan

[joconnell]

Heya Srdjan!

If you use the vray displacement modifier then it only generates polygons for the object at render time so you can't see the result in your viewport. Instead of using this render-time only displacement, you can do something very similar by turning up the poly count of the object that you want to displace with a turbosmooth or tesselate modifier. Then you can apply your displacement map to the object using a regular max displace modifier. Admittedly it will make your viewports slow but you can see how your tiles look before rendering.

[DaForce]

Displacement
http://www.chaosgroup.com/forum/phpB...ght=roof+tiles

Geometry
http://www.chaosgroup.com/forum/phpB...highlight=clay

Take your pick

[Repenseks]

Hello joconnell,

Thanks for the reply, I see what you mean

Hello DaForce,

Thanks for coming yet again to resque me, very good posts, both of them are nice, difficult to choose

I guess, I have to try both ways and to measure time, to see which is fater. I guess, geometry is maybe better, since will not produce artifacts in animation

Regards
Srdjan

[DaForce]

Yeah geometry would be the better solution, but it will be fairly high in the poly count. So do some tests and see how you go.
Maybe you could have a small group of tiles and then just proxy them. Render time will be a little longer but memory usage will be alot lower.

[Repenseks]

DaForce, you are right, in eider case it will be a lots of work.

Uvw mapping will be pain, for every poligon, lots of guess work, for the size etc; while geometry, I was imagening to make one sheet of tiles, make surface with planes, and use boolean to keep only tiles according to the size of the plane. Could I proxy all different pieces of geometry to their places, because instances of the proxys are going to be impossible, if I use that technique...

Regards
Srdjan

[DaForce]

Yeah now that I think about it. Proxying and instance isnt really on, not without a fair amount of instancing, as you would need say 5 or so unique tiles and then instance those alot to make up the roofs. But if you go the geometry way your going to need to do that anyway.

If you go the displacement route it might be alot easier as you could get a tile map and associated displacement map, just uvw it onto the roof and render

[Repenseks]

Only one problem I could see with Vray Displacement is, If I UVW on particular plane, that means I have to somehow UVW Dispacement to mech UVW of the material applyed to that particular poly, If I just use original displace map it will displace wrongly. On the ither hand if I go with max displacement, information for displacement is imbeded into the material itself

Regards
Srdjan

[DaForce]

Huh?? you have lost me.

If you have a nice roof tile diffuse map, with an accompanying roof tile displacement map (so they match up) just map the diffuse map on so it looks good, then use the displacement map so it displaces properly

No fancy mapping needed.

[Repenseks]

DaForce, don't worry, I am also confused myself in the previous post

Let me start from the begenning:

Firstly I choose nice map in the difuse channel in Vray material.

Next I choose poly, and apply that map to it. Then, I use UVW to resize, tile, so it looks ok. Then, I apply Vray displacement modifier. If at that moment I choose grayscale version of difuse map used in Vray material difuse channel, without any tiling, displacement is going to be too big for the object, because, let say I choose in UVW modifier 10x10, and If I apply not tiled map for displacement, it will displace one big tile, in area occupied with 10x10 smaller tiles. Huh, long explanation, but beleive you are going to understand me this time

And another thing, before applying displacement, must I apply another tesselate or somthing else, or it is not necessary?

Regards
Srdjan

[DaForce]

I think you are over complicating this just a little

If you apply a planar UVW map and set the tiling to 10x10 then the displacement map will also be tiled the same.
Or if you tile the map in the vraymaterial then just do the same with the displacement material.
Really easy.

You should not need any tesselate as long as your geometry is nice and neat... like all quads and evenly spaced (ideally)

If you cannot find a good tile map and disp map, let me know I think I have some.