I want to make a custom IItemRenderer that applys a glowing outline to a item. When the item is in hand or on the ground, the outline can be seen through blocks. Basically just like 1.9's glowing effect, except on a item. How would I do this? I don't know much about rendering. Here is my code so far:

 

@SideOnly(Side.CLIENT) 
class GlowRender implements IItemRenderer {
   
   @Override
   public boolean handleRenderType(ItemStack item, ItemRenderType type) {
       return true;
   }

   @Override
   public boolean shouldUseRenderHelper(ItemRenderType type, ItemStack item, ItemRendererHelper helper) {
       return helper == ItemRendererHelper.ENTITY_BOBBING || helper == ItemRendererHelper.ENTITY_ROTATION;
   }

   @Override
   public void renderItem(ItemRenderType type, ItemStack item, Object... data) {
       IIcon icon = item.getIconIndex();
       Tessellator tessellator = Tessellator.instance;
       
       GL11.glPushMatrix();
       
       if (type == ItemRenderType.ENTITY) {
           GL11.glTranslatef(-0.5F, -0.25F, 0.0F);
       }
       
       ItemRenderer.renderItemIn2D(tessellator, icon.getMaxU(), icon.getMinV(), icon.getMinU(), icon.getMaxV(), icon.getIconWidth(), icon.getIconHeight(), 0.0625F);

       GL11.glPopMatrix();
   }
   
}

 

What do I add that makes somthing like this? Or is this even possible with a IItemRenderer?

Bump

If you update to 1.9, you can just add the glowing

PotionEffect

to the

EntityItem

in the world, and be done. Way easier than trying to do it yourself on an outdated

Minecraft

version.

It's just a rim shader that's being applied

I looked up rim shader and it's definitely what I want. But how would I apply a rim shader to the item render? Like I said I don't know much about rendering.

Whoah, slow down.  Rim shader looks like crap on cuboid models.

Not that it isn't worth figuring out how to do, just that it isn't going to do what you think it does.

 

 

The sphere and the cube have the same shader applied to them, the sphere looks pretty awesome because it has a lot of faces and gently changing surface normals.  The cube looks awful because all of its faces are perpendicular to each other, so the angle change is much larger.

 

I think what you need though is to subscribe to a late-stage rendering event and then render the item again with the outline/glow effect only.