How many draw calls is too many

I have an app which displays s of thumbnail images loaded at runtime. I'd like to display the images as they load instead of waiting for them all to load, making a big atlas, and then displaying. Anyway, I read many comments here about draw calls and just wonder what risks I face if my draw calls get too high--plus, what is "too high"? For example, I can get perfectly fine performance with over draw calls. I guess I just don't want to invest too much effort reducing draw calls if I'm not going to hit some kind of insurmountable wall.

Related: how do I know if I am close to exceeding the limit to how many textures Starling can support? Sum up of my lighting rig: - 1 directional light, mixed mode, soft shadows - several point lights, baked only, no shadows - many spot lights, mixed mode, soft shadows - baked GI, resolution at 20 padding at 2, skybox as ambient and reflection source - precompuded realtime, resolution at 1 - directional mode as general GI What I notice: - spot lights shadows seems to be just fine, very good quality, but they does not cast on terrain.

FuzzyQuills , Jun 4, Well all these tests are quite long to rebake each time I'll start a new scene and only add a few objects and lights until I get the expected result. After many tests on a small scene I can say the Baked GI is really buggy This is really sad as it's sounds promising concerning performances.

I managed to come to what I desired as a look and feel in deferred rendering path with a lot of tricks. I was forced to use pretty high resolution: - Precomputed realtime GI resolution at 2 - Baked GI resolution at 60 I used following tricks: - No trees placed with unity terrain brushes, all placed manually, have them set to static.

Grasses kept outside lightmap static. The quality and performances are very good with these settings and the shadows problems almost all fixed, however I'm pretty sure my big scene will fail to build with out of memory message with such settings I'm disappointed. I guess I'll have to stick to realtime lights and have many un-necessary drawcalls for now Unity 5 - How to light large scenes.

How much RAM you guys have on your machines to build big scenes? Last edited: Jun 5, FuzzyQuills , Jun 5, Ah no, will try that, thanks. The only solution so I pray for it to work as I tried to bake my whole scene with a baked GI resolution at 60, but it failed to bake Another question: - Does a scene containing a terrain that is x is considered that big?

It's only 4 times the size of unity terrain I hesitate to split my scene into 4, but I guess I'll have problems with GI seams and will say goodbye to Umbra Occlusion Unless I use the multi scene editing feature in editor and bake Umbra once for all, but what about GI seams if I bake scenes seperately? Joined: Jan 17, Posts: 3, This is a really interesting thread. I am nowhere near an expert with this.

I believe this works correctly with a fully updated version. When I first switched to unity 5, literally no point light shadows would be cast on terrain in deferred and I had to make my own hacked custom terrain shaders.

At some point not too long ago, it seems like the standard terrain shader was corrected. If you're still not getting shadows from point lights, are you using an older version of u5?

Honestly, I've kind of lost track of some of this I spent like a couple hours on it a month or two ago. I really think they resolved the issues. That said there's a page somewhere where you can download various builtin shaders you can search for it, i don't remember the title.

It's pretty simple to hack in - but again - I don't think it should be needed anymore? At least in Unity 5. Thank you very much for the insight, will look at this! If at least I can modify it to cast realtime shadows on terrain, could be cool. As a result, there are many situations where materials are switched while rendering is performed sequentially.

This situation does not effectively reduce draw calls even if several groups of objects share material. Let's see how the draw calls change by changing the Z position of the characters. For simplicity, we tried to make sure that the Z positions are not equal but placed back and forth sequentially. When rendering sequentially according to the Z position, this method prevents the rendering order of the "color-changed characters" meshes and the rendering order of other meshes from being mixed.

The number of draw calls has been greatly reduced from 12 to 4 again. This time, the "color-changed character" is placed first. The draw calls are now 3, which is the minimum expected value, because other characters are intentionally placed so that they can be bundled and rendered at once. This is the most optimized state, but in practice it is difficult to reposition objects to reduce draw calls in the game. Instead, we recommend organizing your scene in such a way that draw calls are likely to be reduced.

Since this function is a " intermidiate optimization phase ", once called, "Draw call optimization is a single character" is retained, but "Draw call optimization with other characters" is no longer performed. Regardless of the color, the draw calls increase slightly to 7. The screen above shows the characters are placed in the same Z position with other same conditions. There are no draw call optimizations, reaching 31, which is a maximum.

Draw calls are internal calculation of the Unity engine, so there are many other causes of increase and decrease in addition to the Z position. Try other ways to optimize drawcalls. There are many conditions under which draw calls can be increased. Below we introduce some features of AnyPortrait that increase the draw calls other than the above functions or color modifiers. If multiple images are used for one character, the draw calls will increase. It may be effective to use one large image rather than several smaller ones.

Please check in advance since it may vary depending on the build environment and devices. Clipping meshes use the Render Texture technique. Due to the feature of the render texture technique, the clipping meshes does not share draw calls with other meshes. Draw calls are increased for both clipping mask meshes and meshes being clipped. If you set the mesh's Shader Settings to something other than the default, this mesh will not be able to share the material with other meshes.

This mesh is changed to be the " lowest optimization phase ". This is the case if you set the Blend method to a value other than Alpha Blend , or use a Material Set that is different from the default. Using the custom properties of the material using script functions such as the SetMeshCustomFloatAll function or the Add Custom Property function on this screen also causes an increase in draw calls. Despite the above explanation, draw calls often increase. In particular, it is difficult to reduce draw calls when many different characters or objects are placed.

If a large number of objects composed of Mesh Renderers appear like AnyPortrait, the draw call can increase significantly. At this time, draw calls can be effectively reduced by using Sorting Group.

This is a scene where two types of characters are placed. Changing a material is expensive because we have to set a new render state. This includes shader parameters and pipeline settings, such as alpha blending, Z testing, Z writing, etc…. Each scenario will result in different batches and SetPasses.

Check the following table. The first and second scenarios are similar: different materials skyrocket our SetPass count. And those have the worst performance hit in the render thread. Batching is not possible, as batching requires using identical materials.

However, we see a hint of light with the third scenario. Sharing materials makes all the difference. Having a unique material reduces the SetPass count to 1, which gives you an incredible performance boost. Sure, we still have three draw calls, but those are very cheap. Finally, if you really want to kick ass, then the fourth scenario is for you. Here, we enable batching. And batching loves unique materials. Enabling batching reduces the Draw Call count to 1.

Before we dig into fighting draw calls, we first need the proper tools to measure them. There are many tools available for this, such as RenderDoc , but we will stick to the simplest: the stats window and the Unity Frame Debugger. You can access the stats window any time by clicking on the Stats button on the top-right corner of the game view.

This panel shows you metrics for the current game view. There, pay attention to Batches draw calls and SetPasses material changes.

As we saw, these are connected but have a different performance impact profile. Lastly, you can and should use the Unity Frame Debugger. My experience has taught me it is crucial to reduce SetPasses and draw calls even if they are not the bottleneck of your game.

Here are my top reasons to reduce draw calls from the start of a project:. You see, while working with Unity you are adding draw calls by default. Assets tend to use different materials unless you pay attention to them. Over time, this will explode. The main requirement to batch draw calls is to get the objects to use the same drawing properties material.

When that happens, Unity can then merge the different meshes into a single chunk that uses the common material. As we said, most assets will use different materials by default. Your entry point is to find out if the objects you want to batch share the same material. Sharing materials is a precondition for batching to work.

Different materials have different drawing settings that change the global GPU render state. There are tools to help you out here. The batching technique I suggest you to use use depends on the nature of the objects you want to batch.

Changing the current shader is one of the most expensive operations you can do. This slows down rendering significantly. Try to reduce the shader count you have in your project including shader variants. So the first step is to remove shaders from your project, whenever you can. Chances are, you can get many original materials to look similarly under a common shader.

Once your target objects use the same shader, the next step is to merge their materials. That is probably complicated, as they probably had different material parameters such as:. Now, if you have several objects with the same material but they must have different parameters, you can give MaterialPropertyBlock a shot. Instead of creating individual material instances, you can create a MaterialPropertyBlock for each renderer that needs custom parameters.

You can then set your individual parameters in each of these blocks. Creating texture atlases for materials sharing a shader often follows this pattern:. I recommend you to do this in your 3d software. If you have the time, this is the best method because it gives you fine control over the process. This will improve the output quality because you can tweak critical variables such as texel resolution. You can also apply more advanced techniques such as palettes.

In no particular order, here are some Unity packages you can use to merge materials within Unity:.