Post rendered images that contain models made with JPatch.


Postby rjh » Wed Sep 28, 2005 4:48 am

Hello all,

Glass (and any other shader for that matter) depends greatly upon how the available parameiters are addressed. In BMRT, one can perform a command on an ".slc" file to see what these parameters are. Other Renderman renderers have similar commands.

"slctell glass.slc" yeilds:

"Ka" "uniform float"
Default value: 0.2
"Kd" "uniform float"
Default value: 0
"Ks" "uniform float"
Default value: 0.5
"roughness" "uniform float"
Default value: 0.05
"specularcolor" "uniform color"
Default value: "rgb" [1 1 1]
"Kr" "uniform float"
Default value: 1
"reflblur" "uniform float"
Default value: 0
"envname" "uniform string"
Default value: ""
"envspace" "uniform string"
Default value: "world"
"envrad" "uniform float"
Default value: 100
"rayjitter" "uniform float"
Default value: 0
"raysamples" "uniform float"
Default value: 1
"Kt" "uniform float"
Default value: 1
"refrblur" "uniform float"
Default value: 0
"eta" "uniform float"
Default value: 1.5
"transmitcolor" "uniform color"
Default value: "rgb" [1 1 1]
"refrrayjitter" "uniform float"
Default value: 0
"refrraysamples" "uniform float"
Default value: 1

Looking at the source file (, these parameters' usage is defined:

* Parameters:
* Ka, Kd, Ks, roughness, specularcolor - The usual meaning
* Kr - coefficient for mirror-like reflections of environment
* blur - how blurry are the reflections? (0 = perfectly sharp)
* envname, envspace, envrad - controls for using environment maps
* rayjitter, raysamples - ray tracing controls for reflection
* Kt - coefficient for refracted transmission
* transmitcolor - color of the glass
* refrblur - how blurry are the refractions? (0 = perfectly sharp)
* eta - the coefficient of refraction of the glass
* reflrayjitter, refrraysamples - ray tracing controls for refraction
* The Blue Moon Rendering Tools (BMRT) are:
* (c) Copyright 1990-2000 Exluna, Inc. and Larry Gritz. All rights reserved.

In the rib file, declare the parameters that are to be altered. Otherwise, the default values are used.

Declare "Kt" "float"
Declare "Kr" "float"

This can happen anywhere prior to the parameter's use. Following is a glass setting that I am using for a current project:

Declare "Kt" "float"
Declare "Kr" "float"

## glass_bell
Color [0.106 0.945 0.588]
Surface "glass" "Ka" [0.3 ] "Kd" [0.1 ] "Ks" [0.5 ] "Kt" [0.95] "Kr" [0.75]
Basis "bezier" 3 "bezier" 3
Patch "bicubic" "P" [-0.044 1.895 ...

Here is a link to the image generated:

There are many more effects that can be generated by manipulating the parameters listed.

Posts: 179
Joined: Thu Dec 30, 2004 10:33 pm

Postby pndragon » Wed Sep 28, 2005 5:20 am

You can get the BMRT shaders reworked for 3Delight here. See the Listing for May 27:
I would have put this link in the wiki but I didn't I didn't know where or if it was even appropriate...

--- Jim
Posts: 591
Joined: Sun Dec 05, 2004 1:27 am
Location: North Carolina

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