Specially for the max people! The Camera Map Per Pixel projection map scales the input image to the size of the render output. So if you want to project a square image, you’d have to set your render resolution to square as well. Pretty annoying, yes? This OSL shader will scale your image back so square really means square!

Download link
http://www.rensheeren.com/osl/camMapScale_tex_v001.osl

Features
– Scales the input image back to its original aspect ratio when using Camera Map Per Pixel.

How to use
VRay:
– Create a VRay OSL Texture map.
– Load in the download OSL shader.
– Plug in the map and set your render and map resolution. The shader will scale the image back to the map resolution.
– VRay — make sure ‘wrap texture coordinates’ (General tab) is off in the OSL shader!

Properties
input_tex
– The texture to scale.
render_width
– Render output width. Only the w/h ratio matters, not pixels. For example you could use width 2 / height 1 instead of 2048 / 1024.
render_height
– Render output height. Only the w/h ratio matters, not pixels.
image_width
– Texture width. Only the w/h ratio matters, not pixels.
image_height
– Texture height. Only the w/h ratio matters, not pixels.
fit_to_width
– Scale to fit to the width when on, when off it scales to match the height.

Code

/*

camMapScale_tex_v001


By Rens Heeren (mail [at] rensheeren [dot] com)

Info Page: http://www.rensheeren.com/blog/osl-cammapscale/


Use as an OSL texture, not as an OSL material.


Simple shader to scale a map back to its original size when using Camera Map (Per Pixel) in 3ds max, as max scales the image
to fit the render size... for some obscure reason.

Usage:
- Plug in the map and set your render and map resolution. The shader will scale the image back to the map resolution.
- VRay -- make sure 'wrap texture coordinates' (General tab) is off in the OSL shader!



Use at your own risk.



2016/05/28 - Created (rh)

*/


//////////////////////////////


shader
camMapScale_tex_v001
(

	string input_tex = ""
		[[ string description = "The texture to scale." ]],

	int render_width = 1920
		[[ string description = "Render output width. Only the w/h ratio matters, not pixels." ]],
	int render_height = 1080
		[[ string description = "Render output height. Only the w/h ratio matters, not pixels." ]],
	int image_width = 2048
		[[ string description = "Texture width. Only the w/h ratio matters, not pixels." ]],
	int image_height = 2048
		[[ string description = "Texture height. Only the w/h ratio matters, not pixels." ]],

	int fit_to_width = 1
		[[ string widget = "checkBox",
		string description = "Scale to fit to the width when on, when off it scales to match the height." ]],
	
	string info_page = "www.rensheeren.com/blog/osl-cammapscale/"
	  [[ string widget = "string" ]],

	output color col_out = color(0),
	output float alpha_out = 0
	
)

//////////////////////////////////////

{
	
	color c_tex = color(0);
	float f_alpha = 0;
	int i_renW = render_width;
	int i_renH = render_height;
	int i_texW = image_width;
	int i_texH = image_height;
	int i_scaleH = fit_to_width;
	float f_U = u;
	float f_V = v;

	float f_rendRatio = (float)i_renW / (float)i_renH;

	if (i_scaleH)
	{
		f_V = ((f_V - 0.5) / f_rendRatio) + 0.5;
	}
	else
	{
		f_U = ((f_U - 0.5) * f_rendRatio) + 0.5;
	}

	c_tex = texture(input_tex, f_U, f_V, "alpha", f_alpha);
	
	col_out = c_tex;
	alpha_out = f_alpha;

}