Altering transparency of material through vlisp

[bcdrane42]

I'm trying to write some simple code that can change the transparency of a material. It seems this shouldn't be too hard but I can't find a way. Any help would be appreciated.

[Hippe013]

Here is the link that was posted in a previous thread about materials. The dxf code that you would be looking for is OPACITY.

 

https://knowledge.autodesk.com/search-result/caas/CloudHelp/cloudhelp/2016/ENU/AutoCAD-DXF/files/GUID-E540C5BB-E166-44FA-B36C-5C739878B272-htm.html

 

Here is a QUICK snippet of code to change that transparency. Many of the folks could on here could write this more elegantly, but this is a quick and dirty get the job done sort of code.

 

(defun c:mattrans ()
 (setq tr (/ (getreal "\nEnter Transparancy: ") 100))
 (setq mats (vlax-get-property (vlax-get-property (vlax-get-acad-object) 'ActiveDocument) 'Materials))
 (setq data (entget (vlax-vla-object->ename (vla-item mats "Glass2")))); Replace Glass2 is the name of your material
 (setq trx (assoc 140 data))
 (setq data (vl-remove trx data))
 (setq elist (append data (list (cons 140 tr))))
 (entmod elist)
 (princ)
 )

 

I hope this at least gets you going.

 

regards,

 

Hippe013

 

P.S. The Value for transparency should be between 0 and 100. When it is placed in the elist it should be a value between 0 and 1.

Edited November 23, 2015 by Hippe013
P.S.

[BIGAL]

Hippe013 could you not just use something like (vla-put-(vla-item mats "Glass2") tr) not tested 1 line v's 4

[Hippe013]

Bigal,

The only way I've seen to edit a material via lisp is through entmod. I can't see any properties available through VL properties and methods. I wish! That would make things a lot easier. Please remember that the code I posted was a quick and dirty way of doing things.

[bcdrane42]

Thanks Hippe013! That was exactly what I needed. I'm proficient in autolisp but very new to the vlisp functions so it will take me time to understand how that works. Thanks for your code.

[Hippe013]

bcdrane42,

I can explain what is going on with the vlisp side of things.

 

The following:

 

(setq mats (vlax-get-property (vlax-get-property (vlax-get-acad-object) 'ActiveDocument) 'Materials))

 

Can be written as Follows:

 

(setq acad (vlax-get-acad-object));Get the acad application object
(setq ad (vlax-get-property acad 'ActiveDocument));Get the Active Document from the acad object
(setq mats (vlax-get-property ad 'Materials));Get the Materials Collection from the Active Document

 

vla-item simply returns object from a collection.

vlax-vla-object->ename returns the entity name of a given vla-object