ZBrush 3 and VRay 4 C4D?

[1066]

Hi all,

I am trying to get an object from ZB to render within C4D (VRay) but I'm not having much look with my displacement.

I can do it perfectly with the AR in Cinema 4D but not via VRay.

Here are my steps for the AR:

1. Import low poly object from ZB
2. Add new material with the PSD image loaded into the Displacement channel with Sub-polygon displacement set to 5 etc.
3. Render and all is ok.

Here are my steps for VRay

1. Import low poly model from ZB
2. Add basic shader to the model
3. Add a VrayDisplacement tag to the object.
4. Load in the disp PSD file and up the amount to about 4cm
5. Render

The disp map shows but it is all squashed into a circle rather than wrapped over the object.

If anyone can show me an example of this working with a simple sphere made in ZB etc then I would appreciate it.

By the way, my scene is set up fine with regards to lighting etc.

Cheers

[Walli]

if you use 4 cm as value, then you need -2 for Shift , as ZBrush normally uses grey as 0 height.

best,
Walli

[1066]

Ok thanks for the quick reply.

I tried that and it's still the same :?:

[1066]

To better see what I mean here is a comparison. Top one is ZB, bottom VRay.

http://img228.imageshack.us/img228/6471/compnl8.jpg

[RenatoT]

Hello 1066,

do you used 2 different projection type or 2 sphere with different UV?

Cheers
Renato

[1066]

Hi RenatoT,

The sphere is exactly the same one. I created the UVs within ZB. I am using the same sphere and the same Disp map as I used for AR and the AR rendered fine.

It does look like some kind of mapping problem but I can't work it out.

On a another note, when I imported the sphere it was really small so I had to scale it up a lot. It was fine with AR, but could this be a problem with VRay?

[RenatoT]

Hi 1066,

can you give me the 2 scene. The one for c4d and the other for Vray?

So i can understand.. :)

Because the UV, in the VrayBridge, are completely managed by c4d.. so it's really strange.

Cheers
Renato

[1066]

RenatoT,

Hi again,

Ok you gave me an idea and I compared the two scenes and for some reason it was on Spherical mapping rather than UVW with a Y length of -100 so it was entirely my fault - sorry.

I'm just a bit overwhelmed at the moment. I honestly thought I would have more problems with it, glad VRay is just as easy as AR with displacement maps.

Thanks for all your help.

[RenatoT]

Hello 1066,

maybe that i'll add a displacement preview in the tag :)

cheers
Renato

[1066]

That would be good :lol:

I have another problem though. The Displacement can be seen but only if I activate the sphere and select "Render Active". If I select "Render Scene" the sphere increases in size and no displacement is shown.

Now I'm really confused. :?

[afternooncoffeeboy]

man thant would be great

[1066]

Ok I have now sorted out my previous problems, the last one seemed to be because I needed to reboot my system.

Anyway, the results I'm getting through displacement are not very good when I use VRay (see image below)

http://img230.imageshack.us/img230/289/comparejs8.jpg

The one on the right with AR is what it should look like, but the one on the left with VRay is just odd.

I am using the same model for both and same disp map.

My VRay settings are as follows:

VrayDisplacement tag settings:

Mapping Parameters
Sampling - MIP
Blur offset/scale - 0%
Amount - 6cm
Shift -3cm (even if I change this it makes no difference)
Keep Continuity - off

Geometry Parameters
On - checked
Use global parameters - checked

Render Settings:

Edge length - 4
Max subdivs - 256
View dependent - checked
Relative - unchecked
Tight bounds - checked

If anyone can help me with this I would appreciate it as I really need to sort this Displacement from ZB out.

Cheers

[afternooncoffeeboy]

ive also problems getting nice displacement results with vrayforc4d. at least with eg. zbrush exported displacement maps...no problems with the c4d shaders though...have to find out wheres the problem

[1066]

Yep it seems it's just with ZB maps. I'm going to have to try messing about with DE3 to see if anything changes.

[stefan]

hi can oyu send us a file where this happens. i cennot reproduce any of this. here it looks good with my maps.

then we look into it:-)

cheers
stefan

[1066]

Ok sure, if you render this scene you should see the messed up displacement. It should look like the Cinema 4D AR render I pictured above but it doesn't.

Thanks for helping Stefan.

P.s I know the scene is bad but it was something I put together in a few seconds. :lol:

http://rapidshare.com/files/57779727/nosevray.rar

[stefan]

thanks!
we look into it

cheers
stefan

[1066]

Cheers, it's appreciated!

[1066]

I've tried everything I can but I'm not getting anywhere. Other than that VRay is the dog's bonkers.

[1066]

I've tried every combination of settings I can think of and still no joy.

Does VRay treat Disp maps differently than AR? If so what would I need to change in the map to get it to work?

Thanks to anyone that replies. If not then I'll have to look for an alternative method.

[1066]

A slight update.

I have manually sub-divided the mesh which gives a better result, however it's still no where near the quality of the AR rendered version.

Also why do I have to manually sub-divide the mesh when I thought Vray did it automatically when you render displacements?

http://img174.imageshack.us/img174/4443/updatexv5.jpg

[1066]

Even though people probably don't read this post I'll ramble on anyway as it makes me feel like I'm getting somewhere (which I'm not) :lol:

Anyway I made it look like the AR version on page one but there were a few holes so I've pretty much given up as I've exhausted all settings in Vray.

I will have to go back to AR for now until hopefully someone eventually works out the ZB to VrayforC4D displacement workflow.

Cheers anyway :wink:

[stefan]

1066 we are aware of your problem, hope we can help soon.
cheers
stefan

[1066]

Ok Stefan, thanks a lot.

[troyan]

We're getting the same issue on a velociraptor model where the displacement looks great in AR but the dino just gets puffier in Vray. No amount of tweaking helps. It definitely could benefit from some sort of displacement preview in the tag.

[stefan]

as said we look into it, maybe this needs an adjustment.
cheers
stefan

[1066]

I don't know if this will help into your investigation but I created another scene for people to test.

Again the Displacement map was generated via ZBrush 3.1.

http://img130.imageshack.us/img130/8656/headtestimagebh0.jpg

http://rapidshare.com/files/58913320/headdisptest.rar

[stefan]

here is a tutorial for max on displacment:

http://www.vray.us/vray_tutorials/vray_displacement_mapping_tutorial.shtml

maybe this helps, try to decreas the edge lenght parameter.
cheers
stefan

p.s could we send this scene to vlado?

[1066]

Yeah I've been through that tutorial.

I've also tried decreasing the edge length, and every other combination I could think of.

If I create a black PSD file and draw on it in white it displaces fine, it only seems to be with the map created from ZB.

Oh and yes you can send the scene to whoever you need to.

[stefan]

we have to look into it, i also have no succes with your file. it seems it doesnt like the UVW mapping. we will send that to vlado probably.

cheers
stefan

[stefan]

we have to look into it, i also have no succes with your file. it seems it doesnt like the UVW mapping. we will send that to vlado probably.

here another tutorial, this works real good p.e.:

http://blog.pixelab.be/2007/09/creating-v-ray-displacement-maps-from.html

cheers
stefan

[1066]

Thanks a lot Stefan.

Interesting idea with that last tutorial.

[noseman]

I must admit that I have had some problems converting Flat texture projections to UVW coords
The result I get is much diffrent on a VRAY material than when I apply "generate UVW coordinates" on a C4D material

is this general?

[stefan]

can you give us a scene noseman?
then we can look at it or try to reproduce.
cheers
stefan

[noseman]

i'm working on this project now. I will use Flat projection for now but will send you a scene ASAP...
thanks Stefan

[Nimpsy]

Has this problem been figured out? I'm having the same issues with displacement from zBrush.

[blewis]

If its a UV problem I have found that sometimes I have to apply the Tag using AR material for the previews to work, then drag the Vray material to replace the same tag. Its sound fishy but it worked for me.