It renders in the inventory fine but not in the world.  (I only have nsew for now just to try and make it work)

 

It also renders the correct shape and bounds of glass panels, just with the default texture.

 

BlockCleanGlassPane.java

package com.cclloyd.ccmodpack.block;

import net.minecraft.block.Block;
import net.minecraft.block.BlockPane;
import net.minecraft.block.material.Material;
import net.minecraft.block.properties.IProperty;
import net.minecraft.block.state.BlockState;
import net.minecraft.block.state.IBlockState;
import net.minecraft.util.BlockPos;
import net.minecraft.util.EnumFacing;
import net.minecraft.world.IBlockAccess;

import com.cclloyd.ccmodpack.CCModpack;
import com.cclloyd.ccmodpack.registry.BlockRegistry;

public class BlockCleanGlassPane extends BlockPane {

public static final String name = "blockCleanGlassPane";
    private boolean ignoreSimilarity = true;
    
public BlockCleanGlassPane() {
	super(Material.glass, true);
	setUnlocalizedName(CCModpack.MODID + "_" + name);
	setHardness(0.3F);
	setResistance(1.5F);
}

@Override
public boolean shouldSideBeRendered(IBlockAccess worldIn, BlockPos pos, EnumFacing side) {
        IBlockState iblockstate = worldIn.getBlockState(pos);
        Block block = iblockstate.getBlock();

        if (this == BlockRegistry.cleanGlass || this == BlockRegistry.cleanGlassPane) {
            if (worldIn.getBlockState(pos.offset(side.getOpposite())) != iblockstate)
                return true;

            if (block == this)
                return false;
        }

        return !this.ignoreSimilarity && block == this ? false : super.shouldSideBeRendered(worldIn, pos, side);
    }
}

 

 

blockstate blockCleanGlassPane.json:

{
    "variants": {
        "east=false,north=false,south=false,west=false": { "model": "ccmodpack:blockCleanGlassPane_nsew" },
        "east=false,north=true,south=false,west=false": { "model": "ccmodpack:blockCleanGlassPane_n" },
        "east=true,north=false,south=false,west=false": { "model": "ccmodpack:blockCleanGlassPane_n", "y": 90 },
        "east=false,north=false,south=true,west=false": { "model": "ccmodpack:blockCleanGlassPane_n", "y": 180 },
        "east=false,north=false,south=false,west=true": { "model": "ccmodpack:blockCleanGlassPane_n", "y": 270 },
        "east=true,north=true,south=false,west=false": { "model": "ccmodpack:blockCleanGlassPane_ne" },
        "east=true,north=false,south=true,west=false": { "model": "ccmodpack:blockCleanGlassPane_ne", "y": 90 },
        "east=false,north=false,south=true,west=true": { "model": "ccmodpack:blockCleanGlassPane_ne", "y": 180 },
        "east=false,north=true,south=false,west=true": { "model": "ccmodpack:blockCleanGlassPane_ne", "y": 270 },
        "east=false,north=true,south=true,west=false": { "model": "ccmodpack:blockCleanGlassPane_ns" },
        "east=true,north=false,south=false,west=true": { "model": "ccmodpack:blockCleanGlassPane_ns", "y": 90 },
        "east=true,north=true,south=true,west=false": { "model": "ccmodpack:blockCleanGlassPane_nse" },
        "east=true,north=false,south=true,west=true": { "model": "ccmodpack:blockCleanGlassPane_nse", "y": 90 },
        "east=false,north=true,south=true,west=true": { "model": "ccmodpack:blockCleanGlassPane_nse", "y": 180 },
        "east=true,north=true,south=false,west=true": { "model": "ccmodpack:blockCleanGlassPane_nse", "y": 270 },
        "east=true,north=true,south=true,west=true": { "model": "ccmodpack:blockCleanGlassPane_nsew" }
    }
}

 

model/block

blockCleanGlassPane_nsew

{
    "ambientocclusion": false,
    "textures": {
        "particle": "ccmodpack:blocks/blockCleanGlass"
    },
    "elements": [
        {   "from": [ 7, 0, 0 ],
            "to": [ 9, 16, 16 ],
            "shade": false,
            "faces": {
                "down":  { "uv": [ 7, 0, 9, 16 ], "texture": "ccmodpack:blocks/blockCleanGlass" },
                "up":    { "uv": [ 7, 0, 9, 16 ], "texture": "ccmodpack:blocks/blockCleanGlass" },
                "north": { "uv": [ 7, 0, 9, 16 ], "texture": "ccmodpack:blocks/blockCleanGlass", "cullface": "north" },
                "south": { "uv": [ 7, 0, 9, 16 ], "texture": "ccmodpack:blocks/blockCleanGlass", "cullface": "south" },
                "west":  { "uv": [ 0, 0, 16, 16 ], "texture": "ccmodpack:blocks/blockCleanGlass" },
                "east":  { "uv": [ 0, 0, 16, 16 ], "texture": "ccmodpack:blocks/blockCleanGlass" }
            }
        },
        {   "from": [ 0, 0, 7 ],
            "to": [ 16, 16, 9 ],
            "shade": false,
            "faces": {
                "down":  { "uv": [ 7, 0, 9, 16 ], "rotation": 90, "texture": "ccmodpack:blocks/blockCleanGlass" },
                "up":    { "uv": [ 7, 0, 9, 16 ], "rotation": 90, "texture": "ccmodpack:blocks/blockCleanGlass" },
                "north": { "uv": [ 0, 0, 16, 16 ], "texture": "ccmodpack:blocks/blockCleanGlass" },
                "south": { "uv": [ 0, 0, 16, 16 ], "texture": "ccmodpack:blocks/blockCleanGlass" },
                "west":  { "uv": [ 7, 0, 9, 16 ], "texture": "ccmodpack:blocks/blockCleanGlass", "cullface": "west" },
                "east":  { "uv": [ 7, 0, 9, 16 ], "texture": "ccmodpack:blocks/blockCleanGlass", "cullface": "east" }
            }
        }
    ]
}

Hi

 

This troubleshooting guide might help

http://greyminecraftcoder.blogspot.com.au/2015/03/troubleshooting-block-and-item-rendering.html

 

-TGG

It helped a little bit but I figured it out.  I didn't need to define the textures one at a time by copying the vanilla json, I just needed to have the json be a child of the vanilla block.

 

blockCleanGlassPane_n

{
    "parent": "block/pane_n",
    "textures": {
        "edge": "ccmodpack:blocks/blockCleanGlass",
        "pane": "ccmodpack:blocks/blockCleanGlass"
    }
}