Rewrite material with alpha
#include <s3d.h>
int s3d_pep_material_a(int object, float amb_r, float amb_g, float amb_b, float amb_a, float spec_r, float spec_g, float spec_b, float spec_a, float diff_r, float diff_g, float diff_b, float diff_a);
Overwriting the latest pushed material, overwriting the current value with the specified one, with alpha value in contrast to s3d_pep_material See s3d_push_materials_a if you want to pep more materials.
Simon Wunderlich
Author of s3d