Bump for non DGS materials

[supergrover]

I've gone through the tutorial in the DevKit that describes how to build an absurdly complex bump map for a DGS material - I can't get this to work for a simple blinn material though as it won't accept the specular input from the mib_colour_mix utility . I don't like DGS ( or I don't get it! ) and I'm happy with the look I'm getting from the Blinn. Is there some way of getting a bump map on to the blinn?? Thanks

[failure]

Why don't you just use maya's blinn?

[supergrover]

Wow - I can't believe I missed that - I've been reading on the forums about how hard it is to get bump mapping to work with Mental Ray and I assumed it wouldn't work with just a basic shader - You have saved my weekend!- Thanks

[joojaa]

yeah it usualy helps if you start (hit f1) by reading the manual and then get misinformed on forums.

Realy the best advice youll ever get is to read all the pages of the help from cover to cover, dont worry that you dont remember it or understand something. When you hit that wall the next time your memory will help you reneber it was discussed in the manual, and presto you know what to do.

And no im not joking, if you wnat to be good you need to act like it.

[failure]

true

[supergrover]

Hi Joojaa - do you know how to get a bump map onto a dielectric material?

[failure]

I don't get the whole "hard to setup the bump map in mr" fuss.
I've set it up in less than five minutes.

It's exactly the same logic as with maya nodes. You just need to make couple of extra connections ( they are implicite in maya shaders, but that's the price of having more control ).

Key thing is to force the "mib_passthrough_bump" to evaluate before actuall illumination/material node, so it perturbes the normal. Convenient method is to use mib_color_mix and connect bump shader to slot 0 and material to slot 1. Bump node wouldn't produce any actual color ( or to be presice it always outputs 0,0,0,0 ),

Where exactly did you stuck?

[joojaa]

mostly the problem stems form the fact that most users dont know how to pwrate mr shaders... And they didnt read the compositing shaders tutorial that sipped eith maya 6. Becasues its a bit hidden form view, alo most people fail to find the mr manual that ships with maya just becasue stheres no direct link in maya helps to it.

[joojaa]

its explained here:

...maya6.0devkitmentalraydocsgettingStartedtextureShaders_bump.html

[failure]

Is this what we are talking about here?

Okay here goes the recipe:

mib_texture_vector1.outValue > mib_texture_remap1.input
mib_bump_basis1.u > mib_passthrough_bump1.u
mib_bump_basis1.v > mib_passthrough_bump1.v
mib_texture_remap1.outValue > mib_passthrough_bump1.coord
directionalLightShape1.miExportMrLight > dielectric_material1.lights[0]
mib_passthrough_bump1.outValue > mib_color_mix1.color_0
mib_dielectric_material1.outValue > mib_color_mix1.color_1
mib_color_mix1.outValue > blinn1SG.miMaterialShader

mib_texture_vector1:
leave default values for picking texture vector from default uv set for poly or implicite uv from nurbs.

mib_texture_remap1:
Repeat: 1, 1, 0
Min: 0, 0, 0
Max: 1, 1, 0
This node is similar to maya's texture placement - so are the placement and repeat attributes ( should be self explanatory )

mib_bump_basis1:
leave default for using surface uv space as bump basis vectors.

mib_passthrough_bump:
Factor: ( strength of bump )
tex: create custom texture entity ( in mr render globals ) and type it's name here. This is bump map texture.

mib_color_mix1:
Num: 2
Weight_0: 0
Weight_1: 1

[press render button]

[joojaa]

yes except in aya 6 you dont need to pluck light connections in!

Its all explained in the mentalreay devkit, yes. However if you didnt install the devkit you might not have those files.

[failure]

I'm one of those deprived people who still work with maya 5

[ybleong10]

how am i going apply a maya default texture (checker,fractal...) to mental ray bump?

[user_deleted]

You could always just download and install the Mental Ray Bump-Combiner shader located in the Maya shaders section of HighEnd 3D

http://www.highend3d.com/maya/shaders/?group=mayashaders&section=&minl=150&maxl=50&numi=266&sort=file_namehttp://www.highend3d.com/maya/shaders/?gro...;sort=file\_name

Its on that page.

This will let you use standard Maya nodes (checker, fractal, whatever) for bump with Mental Ray materials.

Hope that helps : )

-Steve

[ybleong10]

actually i try both menthod, the bumpContainer and mib bump basic. the bumpContainer just work well.

i just feel curious that why the default from mr one(bump basic) cannot work well.i mean it cant work with maya default texture and how to manipulate the texture placement. and i also saw many people recommend to use bump basic from many forum.