Update readme.txt

Author: sunweilun

Diff for: readme.txt

@@ -1,6 +1,16 @@
-Output vertex image is generated from normalized models.
+Usage:
+To render Shapenet models, please refer to the example config file "config.txt"
 
-Normalization Method:
-1. Compute bounding box of the input model.
-2. Move center of the bounding box to the origin.
-3. Scale the model uniformly such that the diagonal length of the scaled bounding box is 2.
+Parameters:
+folder_path = test/  -- root folder of all obj models to render (Remember to put a '/' at the end)
+envmap_path = envmaps/envmap.hdr  -- path of the environment map file.
+theta_inc = 30  -- theta increment of the views.
+phi_inc = 10 -- phi increment of the views.
+phi_max = 30 -- maximum phi angle of the views.
+output_coord = 0 -- output vertex coordinate images or not.
+render_size = 512 -- size for rendering
+output_size = 256 -- size for output images (Actual rendering gets downsampled to antialias)
+reverse_normals = 1 -- default for Shapenet
+brightness = 2 -- overall brightness of output images
+
+Images will be generated in a folder called '[x]_views' under the same directory where the obj model file is located. Where '[x]' is the name of the obj model file excluding the extension.