I’m new (one month) with unity and i’m currently struggling on a problem since some hour now.
I’m trying to optimize a game library by reducing draw calls. After reading the forum i did write a texture packer script to combine my materials and it work great when i use a built-in textured cube object: I can create unlimited textured cube with only 1 draw call.
But if i use an imported model (a tree: one mesh, 59 verts, 54 tris, uv,uv2) then each tree model will sometime use 1 draw call (depending on the camera position it sometime work: 1 draw call for all the model).
I did upload a video to see the problem in action, from what i understand i should only have 3 draw calls in this scene but you can see that it can reach 6 draw calls or more.
Yes i did read that article a lot
As we can see in the video i do respect the guidelines:
No object in the scene is scaled.
They all share the same material and packed texture
No object is more than 100 verts.
I do also have the same problem with a simple cube model from blender. In fact it work if I only use built in cubes. As soon as I pack a prefab AND use a built in cube in the scene (even a simple cube from blender) draw calls will goes crazy even if they do share the same material.
Static batching is not an options as i do not own unity pro
The problem is still actual. Everytime i mix two different object (resulting in 1 or 2 different materials and textures packed with texture packer) the draw calls goes crazy.
I can spawn around 10K verts of the same cube in 1 draw call, either a built in unity cude or a blender made cube.
It seems that we can use a different shader for each of the two model to make the draw call to be as excepted ( 1 draw calls for 500cube1 + 1 draw calls for 500cube2 ) but then it meens we need 1 draw call per model in the scene which is not what is excepted.
Here is again my problem explained which seems to be an unity problem :
Rendering path = VertexLit
Shader = Any
1 directionnal light or no light
Instantiate around 800 built in cube = 1 draw call :
Instantiate around 800 blender cube = 1 draw call :
Instantiate built in cubes and blender cubes = 187 draw call (either with 2 shared or 1 shared material for all the objects)
Instantiate built in cubes and blender cubes with two different shader : 2 draw call
potentially your blender cubes contain more than just position, normal and a uv coordinate (like vertex colors etc) which prevent it from properly batching?
Also did you check if the ‘optimize mesh’ in the mesh import settings help?
Also more important: does it happen if you mix it with other blender meshes of similar complexity or only against unity ones
@Capasjuste I hope its ok to post this in your thread but its kind of related I think.
I read about drawcall batching and found in the docs this part:
“Don’t use scale. Objects with scale (1,1,1) and (2,2,2) won’t batch.
Uniformly scaled objects won’t be batched with non-uniformly scaled ones.
Objects with scale (1,1,1) and (1,2,1) won’t be batched. On the other hand (1,2,1) and (1,3,1) will be.”
I dont understand that part.
a scale of (1,1,1) isnt a scale, is it? Why wont this batch?
and this:
(1,1,1) and (1,2,1) won’t be batched… (1,2,1) and (1,3,1) will be.
First, many thanks for the advices. With your help my main problem seems now to be identified :
The draw call problem occur when i use two different mesh with different property eg. : position, normal, uv, uv2, color etc. The built in cube mesh is “uv, uv2, colors” while my Blender cube is “uv, uv2”.
- Since i don’t know how to add a “colors” attribute to my blender mesh, i did build another blender cube (with different uv texture mapping) but with the same attributes as the other blender mesh (“uv, uv2”) and now all work as excepted. I can batch the 2 mesh in one draw call..
I’m doing more test actually and report back but i’m very happy, thanks for the hint
