Enumerates the different draw command types a BatchRendererGroup can draw.
This is used in BatchDrawRange to say from what draw command stream the batch will read the commands.
| Direct | A direct draw command with a mesh and material. |
| Indirect | An indirect draw command with a mesh and material. |
| Procedural | A procedural draw command. Has a material but vertex data is procedurally fetched by the shader. |
| ProceduralIndirect | A procedural indirect draw command. Has a material but vertex data is procedurally fetched by the shader. |