roof tiles displacement

[noam_farhi]

hi evryone.
i'm trying to displace a tiled roof. i've read the previous posts and learnt a lot, yet i came across one problem that i couldn't solve.
i chose the poygons of the roof i want to displace (the top ones) and applyed the material with the displacement map.
then, using "poly select" i applyed the correctly oriented UVW gizmo and displace mod for evry poly. i used 3d-displacement modifier, checked "use object material". precision is set on 8, face subdiv on 300, keep continuity checked and edge threshold is set on 0.001.

this is the roof object:


this is the somewhat problematic result:




and this is the tileable displacement map i did, in case anyone is interested...


any ideas what's going wrong?
thanx

[vlado]

Disable Max's own displacement mapping from the Render scene dialog, in the Common rollout. You get double displacement - once by max, and once by vray, when you use materials with displacement maps.

Best regards,
Vlado

[noam_farhi]

thanx, vlado, for the unbelieveably fast reply. sure did the trick!

[percydaman]

hehe...straight from the horses mouth..so to speak

percy

[kippu]

wow ....i am trying this out

i been wanting a long time for this ...will test it out now

[michaelinitaly]

Can you post the results? I have never done any thing with displacements, After you applied it to the first section, do you do the same to each section? What is the advantage over using a tileable image?
Sorry if they are dumb questions, I dont have a clue.
Michael

[noam_farhi]

michael, if i would count the dumb questions i asked here i would really feel bad, so don't make me do that that's what this forum is here for, isn't it?
anyway, i would suggest searching this forum for "displacement" and learn a lot, like i did. also, have a look at this:
http://www.syclone3d.com/links2.htm
and also:
http://www.seraph3d.com/bricktut.htm
the trick in my roof was displacing the different polygons in the poly-mesh in different UVWs, and also displacing only the top polygons (to keep the frame of the roof flat, as if the tiles are laid on top of it.
and it's done by selecting the top polys and applying a material with a displacement map in it. then, using poly-select modifier you chose each poly, and apply the correct UVW map for it and the vray displacement modifier, using (for example) the map i shared here.
make sure you use 3D displacement and not 2D, and also check the "use object material" box. also, as vlado said - don't forget to turn off the max displacement in the render dialog box.
another important thing is checking the "continuity" box, so you'll get a nice tight bounds. play with the parameters for this so you will get nice results without wasting too much time (like almost all issues in rendering).
i'll try hunting for the specific posts i've seen dealing with this issue.
i'm sorry, but due to technical problems i can't post the final results at the moment - but they look pretty much like those i posted, only without the problem (try invisioning that )

[noam_farhi]

ok, check these out:

http://www.chaoticdimension.com/foru...nt+poly+select

http://www.chaoticdimension.com/foru...t=displacement

http://www.chaoticdimension.com/foru...t=displacement

[kippu]

ok it works nicely .....now i have to figure out the uvw so that it properly follows the slope ...
mcuh thanks

[C00PER]

You may also want to try this map
http://alexcooper.nm.ru/images/shingles.jpg

[ultra]

it might be easyer to make 3 different elements and displace them intead of one complex element

[noam_farhi]

ultra is right, it is easyer, but in my roof case i wanted the continuity to make a thick effect to the roof tiles, and if it was a different object (the top poly of the roof, i meen), it would look like a tin-made tiles (without thickness). forgot to mention that..
i'll post a closeup shot shortly

[noam_farhi]

ok, here's a closeup on the tiles, showing the thikness i was talking about.

another weird thing i noticed: for some reason the displacement is sensitive to the triangles inside the polygon, as you can notice (on one triangle the slots between the tiles are deeper). anyone has an idea why and how to solve this, if possible?

[losbellos]

I wanted to say previously that you'll have some problem with the bitmap. I think you better remake it, and use gaussian blur only. Vray displacement likes gaussian blur, it will be nice and continous.