add concept of offset to instancebuffer offset

filament/src/details/InstanceBuffer.h

@@ -30,6 +30,7 @@
 #include <utils/FixedCapacityVector.h>
 
 #include <cstddef>
+#include <cstdint>
 
 namespace filament {
 
@@ -54,6 +55,7 @@ public:
     utils::CString const& getName() const noexcept { return mName; }
 
     backend::BufferObjectHandle getHandle() const noexcept { return mHandle; }
+    uint32_t getOffset() const noexcept { return mOffset; }
 
 private:
     friend class RenderableManager;
@@ -62,6 +64,7 @@ private:
     utils::CString mName;
     size_t mInstanceCount;
     backend::BufferObjectHandle mHandle;
+    uint32_t mOffset = 0;
 };
 
 FILAMENT_DOWNCAST(InstanceBuffer)

filament/src/details/View.cpp

@@ -810,7 +810,8 @@ void FView::prepare(FEngine& engine, DriverApi& driver, RootArenaScope& rootAren
                 descriptorSet.setBuffer(layout,
                         +PerRenderableBindingPoints::OBJECT_UNIFORMS,
                         instance.buffer ? instance.buffer->getHandle() : mRenderableUbh,
-                        0, sizeof(PerRenderableUib));
+                        instance.buffer ? instance.buffer->getOffset() : 0,
+                        sizeof(PerRenderableUib));
 
                 descriptorSet.setBuffer(layout,
                         +PerRenderableBindingPoints::BONES_UNIFORMS,