Exporting Bump

[Teriander]

I do not see an option to export a bump map. When I select "Export Model"  I get a list for color, spec, emissive, normal, displacement, and coarse.  But nothing about Bump.  How do I export the bump?  Is that considered the displacement map?

[Tony Nemo]

Yes. It's a greyscale image.

[Teriander]

Ok Thanks!

[alvordr]

Normal is your bump map.  Displacement is something similar, but is used to alter the actual geometry of the mesh.

[Malo]

No.

Normal is Normal, the Blue one. Bump is the grey scale map and Displacement is a different greyscale map.

 

In other word for the TE

No, it is not possible to export a Bump map.

 

You could only export a Displacement or a Normalmap.

[Pix Jigsaw]

I'm a little confused. Someone tell me if I have this right.

 

You can export RGB Normal maps or greyscale bump maps and use them to create the appearance of geometric details on a low poly model.  The greyscale bump maps can be exported by exporting a displacement map from 3D Coat.  Normal maps can be exported by exporting a Normal Map from 3D Coat.

 

Displacement maps exported from 3D Coat can also be used in a different way when exported.  They can represent true geometric displacement (rather than faking it with shading).  Like greyscale bump maps, they are exported from 3D Coat by using the export displacement map option.

 

So, a displacement map exportred from 3DC can be used in two ways:  true geometric displacement or bump map shading.  It really depends on what the external program does with the data in the displacement map.

 

Did I summarize that correctly?

[ajz3d]

I'm a little confused. Someone tell me if I have this right.

You can export RGB Normal maps or greyscale bump maps and use them to create the appearance of geometric details on a low poly model. The greyscale bump maps can be exported by exporting a displacement map from 3D Coat. Normal maps can be exported by exporting a Normal Map from 3D Coat.

Displacement maps exported from 3D Coat can also be used in a different way when exported. They can represent true geometric displacement (rather than faking it with shading). Like greyscale bump maps, they are exported from 3D Coat by using the export displacement map option.

So, a displacement map exportred from 3DC can be used in two ways: true geometric displacement or bump map shading. It really depends on what the external program does with the data in the displacement map.

Did I summarize that correctly?

Pretty much yes. But there's one problem with displacement maps.

Let's consider the following case:

We have our sculpture that we retopologise. Then we bake the normal map and paint some PPP colour/specular/depth textures.

We export the resulting displacement to a file. It will contain only depth information we painted in the Paint Room.

Now, what if we, apart from above map, want a displacement map that contains the differences between the low-poly mesh and our sculpture. We bake the PPP displacement in the Retopo Room and export the displacement map.

We have two maps now. The displacement map that contains depth painted in the Paint Room and the displacement map that contains the differences between the models of different resolution.

How to join them is the question.

For now I use Lighten or Lighter Color blending modes in Photoshop to join those two maps, but this method brings result far from being accurate.

I wonder if someone found a way to export both - the painted PPP displacement and the real displacement into one file?

[Tony Nemo]

In C4D, you can use a displacement map for what is called "SubPolygon Displacement" (differentiated from true vertice displacement which calls for a dense mesh). It's time consuming for the calc but solves the problem of viewed edges that normal maps don't.

[alvordr]

No.

Normal is Normal, the Blue one. Bump is the grey scale map and Displacement is a different greyscale map.

 

In other word for the TE

No, it is not possible to export a Bump map.

 

You could only export a Displacement or a Normalmap.

 

A bump map CAN be a normal map, which is used to fake a change in geometry, or a grayscale map.  A displacement map is for actual geometric changes.  I can, however see where the confusion is in associating a bump map with a displacement map.  As others here have implied, some programs will take a displacement map in the bump map channel.  For instance, you can put a displacement map into a bump map shader slot in 3ds Max.  You can also use a normal map.  Again, in Cheetah3D, the bump map is a grayscale or normal map.  Displacement maps are plugged into displacement.

Edited September 1, 2013 by alvordr

[alvordr]

Here's a link that explains this better.  I recommend watching the video for further clarification:

 

http://textureswithgenetica.com/content/normal-maps-bump-maps-and-displacements-maps

Edited September 1, 2013 by alvordr

[Malo]

Thanks for the Link.

You see it in the Video and in the Pictures.

 

Bump, Normal and Displacement are three different ways to "deform" a surface.

All three works in a different way. Bump fake only in Z axis, Normal fake in XYZ axis and Displacement deform realy the surface.

 

The question is, could 3d coat export a bump map? For me and my understanding is Bump the greyscale map.

The answer is, no it cant, only Normal and Displacement.

 

If you want to use a normalmap as bumpmap is a different question.

Sure this is possible, But i would not recommend it.