Differences

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--- transparency [2020/01/09 09:26] – [Components] admin
+++ transparency [2020/06/02 14:51] – [Order-Independent Rendering] admin
@@ Line 1: / Line 1: @@
 ====== Transparency ======
+__Version:__ 0.8.1+
 Transparency rendering is a huge topic in 3D development.
-A great deal of effort has been put into finding a perfect solution to the problem of correctly displaying transparency.
+A great deal of effort has been put into finding a perfect solution to the problem of correctly displayed transparency.
 The most common but most bad solution is transparency sorting.
@@ Line 10: / Line 12: @@
 [[https://www.khronos.org/opengl/wiki/Transparency_Sorting]]
-The result is incorrect, which some of you already found out by using multiple components of a TTextLayer3D. FMX renders artifacts if rendering order is not correct which leads to bad results.
+The result sometimes is correct, but in more complex scenery mostly incorrect, which some of you already found out by using multiple components of a TTextLayer3D. FMX renders artifacts or even hidden objects, if elements order is not correct, especially for intersected elements.
+Many other methods also have their difficulties in incorrectness, performance-costs, memory-usage or complexicity:
+  * Depth Peeling by A-Buffer
+  * Depth Peeling by linked lists
+  * Moment-Based OIT
 ===== Order-Independent Rendering =====
@@ Line 24: / Line 31: @@
 FMX already provides the "Opaque" property, but was not really used until now.
+{{youtube>5zXlZLWZeVk?medium}}
 ==== Usage ====
@@ Line 35: / Line 43: @@
 ==== Limitations ====
-Weighted Blended Order-Independent Transparency do not know zero transparency colors. This means, if you expect a nearly not-transparent object to be renderedm, it may lead to overlay problems.
+=== Transparency-Limit ===
-Declare an object as "Opaque := false" when you deal with an opacity/alpha value of less than 0.75.
+Weighted Blended Order-Independent Transparency do not know zero transparency colors. This means, if you expect a nearly not-transparent object to be rendered, it may lead to overlay problems. Declare an object as "Opaque := false" when you deal with an opacity/alpha value of less than 0.75.
+=== OpenGL Version ===
+Weighted Blended Order-Independent Transparency is only available for OpenGL v4.2+ and OpenGL es v3.2+. Therefor on Windows platform everything should work fine. This limitation may lead to difficulties on Android platform. **Since OpenGL es 3.2+ is only available since Android 5, we have to configure the NDK to a minimum API level of 21**!
+On Delphi 10.3.3 you don't have to change anything since it is configured to API level 22 by default. But for older versions we have to change it.
+In the end this will lead to a minimum version of Android 5. Older version will not work with your app anymore!
 ==== Components ====
@@ Line 42: / Line 56: @@
 Gorilla3D components are all able to handle the weighted blended order-independent transparency rendering, **but Delphi FMX objects are not**!
-Because there is no general way of intersecting FMX 3D components in rendering, we have to add to some code to each translucent 3D component used.
+Because there is no general way of intersecting FMX 3D components in rendering, we have to add to some code to **each translucent FMX 3D component** used.
 === Inheritance ===
@@ Line 73: / Line 87: @@
 </file>
+=== Alternatives ===
+For many 3D FMX components we provide alternatives, also for layers:
+  * TGorillaCube
+  * TGorillaSphere
+  * TGorillaCylinder
+  * TGorillaPlane
+  * TGorillaTextLayer3D (also optimized for android platform)
+==== Materials ====
+Besides component's setting you'll need a material that outputs all necessary image information for compositing.
+Any extended material of TGorillaDefaultMaterial is able to write that data to the bound framebuffer object.
+You can of course write your own shader. But you'll need to write the compressed fragment color (RGBA) and the alpha
+value (R8) to separated Render targets.
+Next step: [[layer3d|2D FMX components]]