[simmsimaging]

I'm working in Studio and wondering if there are any known problems using Zbrush AUV or PUV tile UV maps and Maxwell displacement? I am testing bringing maps over from ZB and I can't get anything close to right just yet - but mainly my meshes are showing big gaps or totally falling apart/exploding. I have played with recalculating smoothing etc and various displacment sub-d and height values without much luck.

Also: does pre-tessellated disp. work with Fire? Can't seem to get that happening at all.


Thanks in advance
b

[Half Life]

I've had good success with those UV types but the normal smoothing in Maxwell Studio needs to be set really high if you are going to use low poly geometry.

Best,
Jason.

[simmsimaging]

Thanks Jason

Not sure what is going on. Here are some screen caps showing the model in Fire and setting smoothing at 10 and 100 - both still show problems. Interestingly, I tried a quick render of the 100 degree smoothing and you can see the artifacts in MX (versus) Fire are quite different.

Any clues, or anyone else seeing this problem?

As well, I can't get anything going with pre-tesselated and Fire. The sub-d spinner seems to have absolutely no effect at all. Is that just me?

b

[Half Life]

I'll try some things out in the morning when I get back in the studio -- but for now my advice is to set the normal smoothing for 120 and ignore FIRE feedback in favor of the real render.

Best,
Jason.

[simmsimaging]

Ok - I'll give that a try. Thanks Jason

NL: are there known issues with Fire and Maxwell showing displacement differently?

[micheloupatrick]

Also: does pre-tessellated disp. work with Fire? Can't seem to get that happening at all.

I don't know about your zBrush UV problem, but I can tell you that pretesselated displacement works fine with Fire (at least in Maya).
Be warned though that there is a bug : you'll have to convert your disp file from greyscale to RGB first.
See this thread : http://www.maxwellrender.com/forum/view ... 01&t=37665

[Half Life]

After some testing I am able to get Pretessellated displacement working fine within FIRE (in Studio) using a 16-bit greyscale map however I do have to stop FIRE and do a fresh export each time I change the subdivision setting. I would assume this is due to the fact that real geometry changes are occurring, but not refreshing... but it could just as well be that it is taking too long and I'm not being patient enough to wait for it.

For these types of objects I don't think the Pretesselated displacement type is a good choice... the amount of RAM needed to pull off any significant detail is huge... and smoothing appears to be something of an issue as well. Although it does solve the ripped up mesh issue...

Something odd that is happening: Studio does not seem to be acknowledging my smoothing settings in FIRE and it seems to be always using 60... I'm not sure what could be causing this. Fire also has more "missing chunks" of the displacement overall and consistently.

In my tests there is no real difference in Standard UV's and AUV tiles as far as Maxwell output, so that is not the culprit.

Exporting from a higher subdivision (in ZBrush) helps in troublesome areas, but I guess the bottom line is there is no replacing good topology and there are limits to how far a low poly mesh can be pushed with displacement and still hold together.

Also, as a side note -- turn off Interpolation for the displacement (if you don't already), it slows down the render and doesn't seem to contribute much if you have a high quality map already.

I'd be interested to see how all this plays out with the new vector displacement support.

Best,
Jason.

[simmsimaging]

@micheloupatrick: thanks, I am using an RGB displacement map for sure.

@Half Life: thanks for testing that out. I was probably not restarting Fire after changing sub-d levels, I'll have to double check this morning.

I think you are right about the topology. Given that I need really high poly objects for fluids (smoothing doesn't work on refractions, so you really need a good mesh to get clean lines internally) I was hoping to get displacement working to get better responsiveness in the viewports etc., but it's looking like it might not be the way to go with Maxwell.

In any case, I was not pushing the geometry very far with that displacement map. It was not far off what you could do with a normal map, but I was using displacement to see if it would work with refractions - normal mapping wouldn't cut it. Many of the places where it was falling apart should have been 0 displacement for sure though.

I definitely didn't turn on interpolation in the map, but thanks for the heads up on that.

Appreciate the help!

b

[Bubbaloo]

It can break apart displacement if you set the offset > 0, possibly due to the self intersecting geometry this can create. If you keep offset at 0, black will equal 0 displacement while all shades above black will push outward.

[simmsimaging]

Thanks Brian - but then you can't displace in/down correct? That won't reflect the geometry changes in Zbrush - so how would you do that?

[Bubbaloo]

I have seen it "explode" my displacement when I have heavy inward stone displacement on a 90 degree corner of a wall. I will test it more to see if it's causing a problem.

[Half Life]

This will not work for ZBrush sculpts because the displaced surface needs to go in both directions (in and out) thus needs to be set at 0.5.

Best,
Jason.