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olcho
08-21-2007, 10:04 AM
Hi
This is probably a stupid question. I've been poking around to find a solution to this and so far nothing really helpful...
I want to use a normal bump on a surface (I'm using Maya 7-8.5)
The simplest setup would be the make a bump2d node, change the type of the bump to Tangent Space Normal and that's it.
Well, it works, but I have no control.
In Mental Ray, the bump depth doesn't do anything (if I want to make the bump stronger)

I made a test with 3D Studio MAX. The Same scene there, the normal Bump looks great! and I can control it's strength (using bump 3dsmax).

So does someonw know of a way to play around with the normal bump's strength in Mental Ray in Maya?

Thanks

olcho
08-21-2007, 10:19 AM
Found a way! Using bumpCombiner. Works great!
Though I'll be happy if there are other ways, not including installing of additional shaders.
Does anyone know?

royter
08-21-2007, 05:38 PM
you can use any maya shader and turn on bump.

when it comes to MR shaders, there is no shader that comes with a bump slot in it's option.
there is only the mia_material that has it.

olcho
08-21-2007, 07:09 PM
There's more to it, I'm afraid, when it comes to normal bumps.

If you use any regular texture - bump node, they are connected through the texture's outAlpha. So what happenes to all the RGB information, that actually contains the normal vectors information? Even if you turn on Tangent Surface Normals in the bump type, the connection still comes from the outAlpha! May be there's more going on, but certainly doesn't make sence. Another weird thing is, that if I use Maya 7 and render in MR, all of this works - I can change the bump depth to increace/decrease the bump and so on. If I render in Maya 8.5, the bump depth has no effect (may be this is only on my pc).

The only working solution I found, that gave good results is to use Pixero's JS_Normalmapper to get a proper normal bump using the RBG information in the texture and plug it in the bumpCombiner (by francesca), which gives great control over the bump map itself.
All is good, but still it seems a bit odd, that after so many versions of Maya and the normal bump map technique being out for so long, there's no actual properly working, flexible, easy to use, built-in method in Maya.

royter
08-21-2007, 08:25 PM
try to connect a file node to the bump value of the bump 2d node.
then connect the bump2d node to the normal of a misss_set_normal1
connect the misss_set_normal1 to the bump of the mia_material
(don't forget to turn on "export with shading engine" in the mr opyion of the shadfing group of the mia_material.

that's how mr works, you have to have a Phd. in bump maping nodes to apply a simple bump.

cheers

olcho
08-21-2007, 08:35 PM
try to connect a file node to the bump value of the bump 2d node.
then connect the bump2d node to the normal of a misss_set_normal1
connect the misss_set_normal1 to the bump of the mia_material
(don't forget to turn on "export with shading engine" in the mr opyion of the shadfing group of the mia_material.

that's how mr works, you have to have a Phd. in bump maping nodes to apply a simple bump.

cheers


thanks royterr
I'm sorry, I should have mentioned that for this particular thing I can't use mia_material, because I have to do it for Maya 7. And I know about bump map in general in MR. The problem is specific with Normal Bump Map, not the regular bump map, which works fine.

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