how I can get my texture to appear exactly as is defined
 

Interesting question from Worldviz Support Forum at
http://worldviz.us/tt/index.php

Appearance of applied texture at color border -

I have a very simple texture which I apply to a quad. The texture simply is red (255,0,0) everywhere except for a green (0, 123, 0) circle in the center. The texture does not have any anti-aliasing so these are the only two colors which are in the texture.

When it is rendered on a quad, the borders are anti-aliased or something.

Can you tell me how I can get my texture to appear exactly as is defined?

You need to set the appearance mode of your quad to viz.TEXNEAREST. Here is some sample code:

quad = viz.add(viz.TEXQUAD)
tex = viz.add(\'stim-green_123.png\')
quad.texture(tex)

#This will remove mipmapping of the texture
quad.appearance(viz.TEXNEAREST)