Hi,
This is short guide about using ent_create to place obj models in gamestudio 3d. Its wip so can/will be expanded lateron. This is fairly easy and is nothing special, but still a handy feature in some cases.
Why would you want using obj for ent_create? Almost every model program can export a model as an obj. Only a few model editors can export to mdl format. In most cases that isn't a problem since MED can import .obj and export them to .mdl. But what if you want to let users being able to import their own models in your program or game? For example, their own weapon model.
AlternativesOne could give them a link to the gamestudio 3d free version so they can download and use MED. But that's not so professional and most likely only a few people would be willing to take the effort to install an entire external program for such a feature. Another alternative is using an other program that can convert .obj (or other often used formats) to .mdl, that's often a bit more professional if there are easy to install but some cost money and/or are rare. Besides, the more options the merrier.
Placing .obj with ent_create Current features that I know off* Does not break geometry (allows closed mesh)
* Skin support (by using ent_setskin)
/ Animations and bones, haven't tried yet
File requirements This requires a model in .obj (obviously). For exporting from some model programs this requires either notepad for the user or you can add some code in your program/game that removes bad lines the obj file. The reason for this is that some model programs export .obj files with a material and so far from what I have seen, such a material included results in a bad format error when using en_create.
Obj requirements * skin needs to be power of two (e.g. 64x64 or 256x256, 512x512, 512x256 etc.)
* "skin must not be indexed, but normal 24 bit RGB" (quoted from jcl
)
* obj must not have a material (can be removed within notepad but also through code). Look for something like "usemtl ..." and remove this line. Make a backup of your obj file before doing this incase you accidently remove something important lateron (just to be safe).
Code test example (with texture), don't forget to place the obj model and your texture in the same folder
///////////////////////////////
#include <acknex.h>
#include <default.c>
///////////////////////////////
BMAP* tex = "BlockTex.bmp"; //your texture
function main()
{
vec_set(screen_size,vector(800,400,0));
vec_set(screen_color,vector(155,155,155)); // grey
vec_set(sky_color,vector(155,155,155)); // grey
video_window(NULL,NULL,0,"Obj model test");
d3d_antialias = 1;
shadow_stencil = 1; //to test closed mesh
level_load(NULL);
vec_set(camera.x,vector(0,0,100));
vec_set(camera.pan,vector(0,-90,0));
you = ent_create("ExportBlock3.obj", nullvector, NULL); //place big model
you.scale_x = 10;
you.scale_y = 10;
ent_setskin(you, tex, 1);
you = ent_create("ExportBlock3.obj", vector(0, 0, 10), NULL); //place small model above for shadow testing
set(you, SHADOW);
you.scale_y = 4;
ent_setskin(you, tex, 1);
while (1)
{
you.pan += time_step*3;
you.tilt += time_step*3;
wait(1);
}
}
There are several possibilities here and the material line could be different for each model program that exports the obj (also since some programs export with line breakers and some do not). What works for me is first txt_load, change the strings with the GS3d string functions and than save them as .obj again. Than you can load the new .obj file with ent_create.
Programs tested with and instructions 
Create your model. File -> Export -> Wavefront (obj) -> uncheck 'write materials' -> [export].
Create your model. File -> Export -> 3d model -> select obj as type -> [export]. Open obj file in notepad or through code, delete the "usemtl ..." line (without quotes, example: usemtl _Brick_Rough_Tan_1). Be carefull, some Sketchup functions allow users to break their mesh iirc.
Photoshop works? Damn right it does, by using 3d layers. Though with a minor problem though that has nothing to do with ent_create+obj. Photoshop export to .obj always destroys the mesh, whether you import it with MED or load the obj directly with ent_create. Note that I have only tested this with cs5, so for newer version this may be fixed but I doubt it. Cause of closed mesh this cannot be used for stencil shadows etc. but for other stuff it doesn't matter I think.
Ok
how to do it: File -> New -> 3D -> New shape from layer -> Export 3d layer -> Wavefront (obj). Now open the obj in notepad and search for mtl.... lines and remove them (like usemtl Left_Material).
Hope this is usefull for some. Will be expanded later on. Cheers.
