View Full Version : DGS material + bump?

05 May 2003, 09:06 AM
Iīm using DGS Material pretty much now and I was wondering how can I attach some Bump info to the shader, In MAYA you have a Bump tab, but in DGS material (but I noticed that all the MR custom shaders donīt have any bump tab) there is no bump info, how can I make it?

06 June 2003, 11:44 PM
I have found a simple solution to this problm..actually, I didn't, but someone else did and they created a plug in called " reflection utility". You can download it on high end 3d. It creats a custom node you can connect to the reflection color to control diffuse reflections in MR. Better still, you can control the sampling on a per shader basis, so no more rendering MR a 2 4 sampling

06 June 2003, 01:05 PM
Well, thatīs a great workaround but, what if I want to use DGS material?, (or any Mr custom material instead), there must be a way to atach some bump to them donīt you think so?.
Thankīs for your tip anyway!


06 June 2003, 02:21 PM
Don't have maya where i'm now, but if i recall corectly you can use a normal maya shader, with bump, and connect the dgs_material just to the material slot of the shader group (in the mental ray section)

I may be completely wrong, though, my memory is out of business today

06 June 2003, 07:31 PM
I donīt remember either, but I think it doesnīt take any bump info into consideration, it acts as a layered shader so it overrides every kind of information it has below him... I think.

06 June 2003, 08:54 PM
When you use a mr custom shader as a material shader it overrides all of the maya shader attributes, so nothing you do to the maya material has any effect.

06 June 2003, 11:25 PM
Well, there IS a bump map custom MR node, but i have yet to figure out how to use it, as i'm just starting to wrap my head around the whole process of writing/using custom shaders..

Bump Mapping

Apply a texture to the normal vector by evaluating the texture at multiple points to compute U and V gradients that are multiplied with the basis vectors, combined with the original normal, normalized, and written back. Also return the normal. state - > tex is left undefined.

vector "mib_bump_map" (
vector "u",
vector "v",
vector "coord",
vector "step",
scalar "factor",
boolean "torus_u",
boolean "torus_v",
boolean "alpha",
color texture "tex")

u and v are the bump basis vectors. They can be generated from another base shader such as mib_bump_basis.

(from the MR docs)

06 June 2003, 08:02 AM
brunner:) can you give me an example~~~THANKS

06 June 2003, 10:25 AM
Well, you can always attach a bump custom MR node, but youīll have to connect it to somewhat either..., or may be you can connect .outNormal of the Mr bump node to the .inNormal of DGS Mr custom Shader..., is this possible?, iīll give a try...

06 June 2003, 12:49 PM
Originally posted by beggar_xieyu
brunner:) can you give me an example~~~THANKS
Hell, i whish i could :)
With these exams i have no time to experiment, unfortunately..

06 June 2003, 07:57 PM
from Maya release notes >

Bump mapping and custom mental ray shaders
Bump nodes are not directly supported by mental ray custom shaders.


Bump effects are still achieveable and involves setting up your network to force bump nodes to evaluate during the render.

To get bump to evaluate, you need to map your bump nodes to one of the spare attributes on your custom mental ray material shader (that is currently not mapped).

However, if you want to use all of your material's attributes, then you need to pass the texture you really want showing up for that attribute and the bump nodes via a mib_color_interpolate node (which behaves similar to Maya's ramp texture).

First, assign your texture to the Color_0 attribute of the mib_color_interpolate node and then assign a mib_passthrough_bump_map to Color_1 attribute of the mib_color_interpolate node.

Next assign the mib_color_interpolate to any of your material's attributes (example: diffuse color) and set the input value of the mib_color_interpoloate node to a low value like 0.001 which will force the bump to evaluate while allowing you to also use the other texture for diffuse color.

06 June 2003, 02:25 AM
can you tell me which mental ray's node do use to assign texture to the mib_color_interpolate.
I used MAYA's file node ,hehe~~~:p
API 0.0 error 301090: undefined ctexture symbol ""
API 0.0 error 301105: undefined color texture ""
API 0.0 error 301090: undefined ctexture symbol ""
API 0.0 error 301105: undefined color texture ""
HELP ~~~~~~:p

06 June 2003, 08:13 AM

I wrote that release note :)

I'm in the process of creating some mental ray for Maya tutorials and will make one for bump mapping with mental ray custom shaders.

I'll put them on my website - stay tuned.

beggar_xieyu: try creating a custom file node via the mental ray Render Globals window.

Custom Entities -> Custom Textures -> Create

Then go into Hypershade and connect freely.


06 June 2003, 09:06 AM
Farhez you will bring some light to these terms, it seems Alias|Wavefront donīt want us to use MrForMAYA, there is no help at all (almost useless help) and no information around the inet..., Iīll be waiting for your news and tutorials.

Thankīs in advance!

06 June 2003, 05:06 AM
I get the same feeling Joie.

Im addicted to the smarts of MR, but cannot run it worth crap.

I know it is very customiseable (sp) like Houdini and more geared at coding, whereas I am a GUI guy. However, it is driving me mad trying to find a way to learn it.

Farez, I am very anxiouse to see your tutorials.

take care all,


06 June 2003, 03:25 AM
where are your tutorials:p .

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