To summarize I print the matrix (projection*modelview) to a file. In the shader I use a static mat4 with those printed numbers, but the results are not the same as using gl_ModelViewProjectionMatrix; In software, I did this (in pseudocode): float model[16], projection[16], final[16]; glGetMatrix(GL_MODELVIEW, model); glGetMatrix(GL_PROJECTION, projection); glLoadIdentity(); glMultMatrix(projection); glMultMatrix(model); glGetMatrix(GL_MODELVIEW, final); <<----I saved the final as (projection*model); In the shader I use: //modelview is actually (projection*modelview) as previous line above shows. gl_Position = gl_ModelViewMatrix*gl_Vertex; This works perfectly fine. But if I print final to a txt file, and use a static mat4 final = mat4{final[0], final[1].......), then this code doesnt work: gl_Position = final*gl_Vertex;

What happens if you use 'final' in your shader? Nothing gets displayed or the object being rendered is not proper?
How are you passing the array 'final' to your shader ?
Is it passed correctly ? I dont see any other reason.

I don't see anything wrong with your code.

Anyway, is there a particular reason you are doing it this way?

It's best to upload you projection matrix to GL_PROJECTION and modelview to GL_MODELVIEW

and in your shader, just stick a

gl_Position = ftransform();

When I use final, I'm not sure exactly what it does but its not right.

I can't use ftransform() as its for skeletal animation. Which btw, What is the proper way to send a mat4 to a shader?

Put this in shader
uniform mat4 mymatrix;
and get the location and then
glUniformMatrix(location, FALSE, array_with_matrix, 1);