Apps similar to ModLab include AwesomeBump, which is free and open source. Other options are Materialize - by Bounding Box Software, Quixel Suite, Laigter and xNormal. You can choose from more than 10 Game Development Tools like ModLab for Windows, Linux and Mac.
AwesomeBump is an open source program designed to generate normal, height, specular or ambient occlusion textures from a single image. Since the image processing is done in 99% on GPU the program runs very fast and all the parameters can be changed in real time.
Materialize is a stand alone tool for creating materials for use in games from images. You can create an entire material from a single image or import the textures you have and generate the textures you need.
Canada
Quixel was founded in 2011 by Teddy Bergsman and Waqar Azim, based on the vision of substantially speeding up how creators build digital environments, by giving them access to a vast and ever-expanding library of 3D building blocks, and easy-to-use tools to greatly simplify the...
United States
This tool lets you generate normal maps for 2D textures, with little effort. Specially designed for Sprites in 2D games.
xNormal is an application to generate normal / ambient occlusion / displacement maps. It can also project the texture of the highpoly model into the lowpoly mesh ( complete texture transfer, even with different topologies ).
This is a suite of ten Gimp plugins known as the 'Resynthesizer'. The most commonly used is 'Heal selection' but all use the plugin whose full interface is found at 'Filters>Map>Resynthesize.
Crazybump generates lighting maps from 2D textures. It supports ambient occlusion (AO) maps, bump maps, normal maps, and more.
Converts a bitmap into a seamless PBR material, including normal, AO, roughness and metallic.
SpriteIlluminator lets you easily generate normal maps for your 2d game and web projects. Render dynamic lighting & other effects and use paint tools to directly draw on the normal map and fine tune the effects.
Sprite Lamp is a software tool to help game developers combine 2D art with dynamic lighting effects, through the creation of hand drawn normal maps.
Australia
Knald is the world’s first GPU powered solution for generating “bake quality” textures from any 2D source texture.
NVIDIA Melody creates high quality normal maps that make a low-poly model look like a high-poly model. Simply load your low-poly working model, then load your high-poly reference model, click the "Generate Normal Map" button and watch Melody go to town.
