I'm playing around with Google's new Augmented Reality SDK.
Their example project contains an .obj file but its' textures are not in a .mtl file, put a .png file; no .mlt file at all (example for an Android robot model below).
From a little research I take this is not the 'standard' procedure of exporting a model / it's texture in the .obj format from Blender (or similar programs).
Is there a way to still achieve this (textures in .png instead of .mtl) with Blender?
The .mtl file is only a material definition file which contains references to textures.
if you want to export obj with .mtl and textures you need to make sure you follow these steps:
In your OBJ export menu:
You will see that in your target folder you now have
To export an image texture at Blender do the following:
Select your object and enter in edit mode. Select all vertices/faces (press 'a'). Then start the UV Mapping, press 'u'. And Select one of the options of the UVMapping. You must test the best option for you model.
Then go to the UV/Image Editor:
Export UV Layout at the menu, and save your image.
Another easy way, but off topic way, to get a png out of an mtl, is to make a Roblox account, download Roblox studio.
Make a new baseplate game, insert a meshpart and then go to View -> Properties and then enable properties tab, then look at the properties tab of the meshpart and then you should see a folder button on the side of the mesh section, and then click it, insert your mesh, and under the mesh id, you should see a texture.
Copy the id, only the numbers, then type in exactly this and replace (insert id here) with your id: roblox.com/library/(insert id here)/name and then it should redirect you to a link with the image.
If it has an image of a piece of paper and an hourglass, you need to wait for it to be an approved image.
ensure your object has uv's and then bake out the map you want to a texture using the bake section in the render settings.
