Banded Mushroom

[Guest jandals]

Has anyone got an idea on why my mushroom is banded like this? I have an animated decal (QT movie) as a displacement map but it hasn't got THAT much compression in it. And look at the underside of the "crown;" it's like a surface break...

 

The surface it pretty hi-res; a 40X40 patch grid rolled into a tube.

 

I'm working of this tutorial and Weevil doesn't run into any of this...

 

hash.com/users/weevil/

 

EDIT : Part of it turned out to be a poorly-compressed transparency decal. But there's still more going on in this image. ANy ideas?

 

Rhett

[KenH]

Are you using multipass or no?

[pleavens]

In the animated displacement tests I have done..

 

Animated displacement map stuff.

 

I found it critical to use uncompressed video. The problem is that the compressed video will create slight variations of the grayscale value which will mess up your intended displacement.

 

Phil

[Guest jandals]

No Multipass. I'll give it a shot.

 

I just rerendered the maps so I'll bring it uncompressed in to AM next time.

 

Thanks, guys

[Guest jandals]

I found it critical to use uncompressed video. The problem is that the compressed video will create slight variations of the grayscale value which will mess up your intended displacement.

 

Phil

I'm using A:M to render the displacement maps and the compression bands are in the .TGA's that it produces. Is there any way to get around that?

[lazz]

Can we see a wireframe? I'm thinking it has to do with alphas and gammas if its a higher patch count, does it do this without the texture as well?

[pleavens]

I found it critical to use uncompressed video. The problem is that the compressed video will create slight variations of the grayscale value which will mess up your intended displacement.

 

Phil

I'm using A:M to render the displacement maps and the compression bands are in the .TGA's that it produces. Is there any way to get around that?

 

You can try running a "threshold" image adjustment followed by a gaussian blur on the tga sequence. That should even out the surface yet provide the displacement you want.

 

Phil

[Guest jandals]

Here's a wireframe shot with a couple rendered sections. Note that the displacement is driven by a procedural material.

 

I do get some gamma/alpha issues but I can fix those by "refreshing" the mesh and, if I remove the texture, I get a nice smooth render.

[pleavens]

Here's a wireframe shot with a couple rendered sections. Note that the displacement is driven by a procedural material.

 

I do get some gamma/alpha issues but I can fix those by "refreshing" the mesh and, if I remove the texture, I get a nice smooth render.

 

I'm confused, are you doing the displacement with an animated quicktime decal, or are you using an animated procedural material?

 

Phil

[Guest jandals]

I'm confused, are you doing the displacement with an animated quicktime decal, or are you using an animated procedural material?

 

Phil

I've done both. And I get the same banding in each case. I've sent this scenario to Hash; hopefully they'll turn up something.

[pleavens]

I'm confused, are you doing the displacement with an animated quicktime decal, or are you using an animated procedural material?

 

Phil

I've done both. And I get the same banding in each case. I've sent this scenario to Hash; hopefully they'll turn up something.

 

If you want, I'll be happy to look at the procedural version of the model.

 

Phil

[Guest jandals]

Sure Phil, Thanks!

 

Here's the .prj.

JRJMushroomRep.prj.zip

[pleavens]

Sure Phil, Thanks!

 

Here's the .prj.

Looks like there were several things that might have contributed to the banding.

 

1. The scale of the "cloud" model was very different then the scale of the "profile" model. This caused the "cloud" to be very compressed to fit the action.

2. The density of the "cloud" model is probably much higher then needed for this usage of displacements, not to mention a greatly increased render time requirement.

 

The attached project has the mods I made. As the cloud model was scaled down to match the profile, the materials gradient position no longer matches what you had and will have to be re-adjusted.

 

Be careful with the material, adjust it at the model level as making adjustments at the material level does not override the drivers.

 

If I were doing this from scratch, I would make everything at a much larger scale, as it is to keep your Shroom action working, it was necessary to scale the material and it's percentage of displacement down dramatically.

 

[attachmentid=10536]

[attachmentid=10535]

JRJMushroomRep_mod.zip

[Guest jandals]

Wow, My hero! Thanks Phil!

 

I often forget to check the scale of my models. This is the first time it's caused a headache like this.

 

As for the density of the cloud mesh... that's what was suggested in the tutorial I followed. THe author recommends using a dense mesh because patches are broken into only 16 subdivisions when performing displacement. Maybe that's no longer true (or just not an issue) in v12?

 

I'm back to work on this. Thanks again for your help!

 

Rhett

 

EDIT: I took out 5 spline rings (from the original 40) and it's already made a difference...

[Guest jandals]

I think stretching the mesh from it's initial length (in the chor) may have had something to do with it.

 

Here's how it looks now: