Is There A Displacement Mapping "Edge" Work Around

[Michael J. Brown]

Is there a way to elliminate the edge separation effect that happens when displacement mapping is applied (V-Ray...though it happens in MR too)?

 

I know it's effects can be lessened by filleting or chamfering (with multiple segments) the edges of an object. But is there a way to completely avoid or revearse this side-effect?

[Chad Warner]

You can put a negative value in the "shift" slot.

[Michael J. Brown]

You can put a negative value in the "shift" slot.

 

Been looking all over for this "shift" slot you referenced, Chad. I did try placing a negative value in the Displace value slot (in the Maps rollout - V-Ray) and it cured the edge condition. But it also nullified any displacement effects. I even tried it with a -100 displacement and still no dice.

 

Where is this "shift" slot?

[Stephen Thomas]

Chad is talking about the 'shift' value directly below the 'amount' in the vray displacement modifier rollout. However all you really need to do is check the box at the bottom that says 'keep continuity' and that will keep your corners together. I just found this out recently and had many headaches with this issue in the past too!

 

Edit: you need to be using 3d mapping to access this option though.

[Michael J. Brown]

Oh.... No wonder i couldn't find it. I'm not doing displacement via a modifier, but instead through the material itself.

 

Which method is the most economical in terms of processor / memory load - via material or modifier?

[Stephen Thomas]

I think Vray automatically overrides the material displacement, so both are the same to render as far as I know. You get much more precise control over the amount, variation in length etc. with the modifier though, as well as solving the problem you were experiencing.

 

Generally 2d mapping is quicker than 3d, so use that for things like grass etc., but for solid objects where you have corners to deal with use the 3d option.

[luckymutt]

(V-Ray...though it happens in MR too)?

A quick note for this happening in mental ray (not sure if it applies for vray at all)...

When creating displacement via material, set the polys along the edges in question to the same smoothing group. You may still to add edge loops though to keep it from pushing out in a wonky way.