Map test

Started by yossam, March 31, 2015, 03:09:25 pm

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Dune

Regarding normal maps, why are they blue? If you use them as bumpmap, better make greyscale and increase contrast.

PabloMack

Quote from: j meyer on April 03, 2015, 11:34:10 amThe look of the last pics seems to indicate that your model might have no normals,thus the facetted appearance.(normal smoothing doesn't work without normals)


I don't think this makes sense. If your object has polygons then those polygons have normals. It might be more complicated to compute what the normal is if the vertices of a polygon were not co-planar but there is still a normal.

j meyer

PabloMack - some apps don't export normals to keep the file size reasonable.
                 In most modeling packages and modelers you won't notice,because
                 they generate the normals automatically.TG does not.That why it's
                 noticeable.
                 Recently talked about it here:http://www.planetside.co.uk/forums/index.php/topic,19091.30.html
                 Just scroll down a bit.
Edit: sorry for the not working link,don't know what happened.


Ulco - there is a difference and some apps prefer normal maps others bump maps.
         Don't know why it evolved like that.Maybe the wikipedia does.

yossam

This is with no maps, nada, ziltch, 0......................

Dune

Did you set 'use smooth normals' in TG? What if you take this through Poseray, calculate smooth or at least say 60ยบ normals, export and texture procedurally in TG?

PabloMack

April 04, 2015, 08:23:38 am #20 Last Edit: April 04, 2015, 10:25:37 am by PabloMack
Quote from: j meyer on April 03, 2015, 01:16:56 pm
PabloMack - some apps don't export normals to keep the file size reasonable...


I guess there are two benefits from having the normals specified in a separate
data structure. One is so that the program receiving the object doesn't have to
deal with computing them. The other is so that they could actually be computed
to point in a direction other than what the geometry would imply. But the practice
of having to precompute values that are already implied in the data structure is
not very efficient. As you say, some applications don't include it to save file space.
Since this information is implied in the geometry then it is already there but must
be computed to make it available. I guess the ultimate goal here is that a displacement
map needs to relate how much displacement there is going to be using a UV map
to scale the displacement in the normal direction by an amount in a UV mapped
image. We are talking about a data structure now that needs a lot more information
than just normals. But I guess you are telling me that, even if you specify a UV
displacement map, if the normals that are referenced in the UV displacement map
are not provided as a separate data structure (internally in the object) that TG
does not compute them from the geometry so that the UV displacement map
will be ignored?

j meyer

yossam - no maps at all looks the same as the one with displ map only.That's strange.
             The displ map should have an effect rto on or off.Occasionally one has to crank
             up the value quite a bit.Other than that I've no idea at the moment.
             Is the rock a ZBrush made object?
             Anyway,you can use poseray to add normals.

PabloMack -
QuoteBut I guess you are telling me that, even if you specify a UV
displacement map, if the normals that are referenced in the UV displacement map
are not provided as a separate data structure (internally in the object) that TG
does not compute them from the geometry so that the UV displacement map
will be ignored?

Nope,displacement maps and such should still work as expected.

Upon Infinity

Quote from: Upon Infinity on April 03, 2015, 02:04:45 am
It could also be that some renderers support not only displacement maps, but also bump maps, as well, giving you not only the displacement (which is rougher) but also the fine (fake) detail of the bump map.


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yossam

Here is what I could find out about the workflow for the rocks. To start they used photogrammetry to construct the mesh. Autodesk ReCap360 to Zbrush for more modeling, from Zbrush to Mudbox for texture painting and retopology. I am not that familiar with any of the software mentioned..............maybe that could be part of the problem.  ???

Dune

This kind of rock is fairly easy to make, also in LW. Texture it procedurally and you're fine. And I think with some clever PF's you can build these shapes within TG with displacable cubes, or even fake stones or a rock population.

j meyer

As for the facetted look it could be caused by ZBrush not exporting normals,but I don't
know,if mudbox does export normals or not.The effect could be caused by a wrong
creasing also.Both can be fixed with poseray.To change the crease settings you have
to change the creasing value in poseray before you import an object as far as I know.
Maybe more than one try required.
Still no idea why the displ map seemingly doesn't work,sorry.