So I am trying to render an Item (eg. an IronPickaxe) with an ISTER. Currently I am using the following code:
matrixStack.push();
matrixStack.translate(0.5D, 0.5D, 0.5D);
ItemRenderer itemRenderer = Minecraft.getInstance().getItemRenderer();
itemRenderer.renderItem(baseItem, transformType, combinedLight, combinedOverlay, matrixStack, buffer);
matrixStack.pop();
where baseItem can be any Item (eg. an IronPickaxe).
The item is rendered fine, except for the Inventory where it appears to be darkend.