Differences

This shows you the differences between two versions of the page.

--- 0.8.4:volumerendering [2022/05/05 12:37] – [Gamut Mapping] admin
+++ 0.8.4:volumerendering [2022/06/16 13:47] (current) – [Filtering and MipMaps] admin
@@ Line 262: / Line 262: @@
   FFrontFaceRenderPass.FaceKind := TFaceKind.FrontFace;
   FFrontFaceRenderPass.Viewport := GorillaViewport1;
-  FFrontFaceRenderPass.Enabled := true;
   // a pre render-pass to get all vertex positions of back faces
@@ Line 268: / Line 267: @@
   FBackFaceRenderPass.FaceKind := TFaceKind.BackFace;
   FBackFaceRenderPass.Viewport := GorillaViewport1;
-  FBackFaceRenderPass.Enabled := true;
   // create the volume mesh
@@ Line 277: / Line 275: @@
   FVolume.FrontFaceRenderPass := FFrontFaceRenderPass;
   FVolume.BackFaceRenderPass  := FBackFaceRenderPass;
+  // only the volume itself should be rendered for front/back face detected
+  // this will ignore all other objects.
+  FFrontFaceRenderPass.AllowControl(FVolume);
+  FFrontFaceRenderPass.Enabled := true;
+  FBackFaceRenderPass.AllowControl(FVolume);
+  FBackFaceRenderPass.Enabled := true;
   // configure some settings
@@ Line 353: / Line 358: @@
 |Gamut|Texture used for mapping the 3D value during Raytracing|
 |GamutMode|Defines when and how the value-color mapping happens. Here different modes are available: GamutNone, GamutByValue, GamutByValueMultiply, GamutBySum, GamutBySumMultiply|
-|GamutFactor|A factor applied to the absolute 3D value before mapping onto the gamut texture (default value is 1.0)|
+|GamutFactor|A factor applied to the absolute 3D value before mapping onto the gamut texture (default value is 1.0). Use this value for shifting inside of the gamut texture. |
+|GamutIntensity|Defines how intense coloring is.|
+|GamutAlphaIntensity|Defines how intense alpha channel coloring is.|
 {{youtube>cmgTMz4PDAc?large}}
 === Modes ===
@@ Line 367: / Line 375: @@
 |GamutBySum|Gamut mapping will be applied to the final casted ray value.|
 |GamutBySumMultiply|Gamut mapping will be applied to the final casted ray value and afterwards multiplied with the previously computed color value.|
+===== Lighting =====
+Since v0.8.4.2314 lighting and iso surface detection is also supported.
+To activate lighting for a volumetric mesh, please use:
+<file pascal>
+GorillaVolumetricMesh1.UseLighting := true;
+</file>
+After it was activated, the implemented functions try to detect a surface from the given 3D data.
+This is called IsoSurface detection.
+Because this method always depends on the data, you can control this detection by **IsoSurfaceLimit** property.
+{{:0.8.4:vr_isosurf.jpg?nolink&600|}}
+<file pascal>
+GorillaVolumetricMesh1.IsoSurfaceLimit := 0.125;
+</file>
+When detection of a volume surface was successful, we are able to apply lighting with all available shading models to it.
+The volumetric mesh therefore allows to choose between: Lambert, Phong, Blinn-Phong and PBR.
+{{:0.8.4:vr_lighting.jpg?nolink&600|}}
+<file pascal>
+GorillaVolumetricMesh1.ShadingModel := TGorillaShadingModel.smPBR;
+</file>
+__Notice:__ For PBR (physically based rendering) it does not need any PBR texture, instead it will use the //AOBias//, //RoughnessBias// and //MetallicBias// properties.
+{{youtube>zMfiPLPDcq0?large}}
+===== Filtering and MipMaps =====
+Since v0.8.4.2314 switching between nearest and linear filtering is supported.
+You are also able to activate MipMaps, but in most test cases the result was unsatisfying.
+{{:0.8.4:vr_filtering.jpg?nolink&600|}}
+The picture above is showing difference between nearest (left) and linear (right) filtering.
+In most cases linear filtering is the expected output, but for some customers exact display of 3D data values is necessary.
+<file pascal>
+GorillaVolumetricMesh1.LinearFiltering := true;
+GorillaVolumetricMesh1.MipMaps := false;
+</file>
 ===== Multiple VolumetricMeshes / Complex Scenes =====
@@ Line 390: / Line 450: @@
 // exclude all other volumetric meshes or other objects - that the render pass only renders the relevant volume
-FFrontFaceRenderPass1.IgnoreControl(FVolume2); // !!! only compute Volume #1
+FFrontFaceRenderPass1.AllowControl(FVolume1); // !!! only compute Volume #1
 FFrontFaceRenderPass1.Enabled := true;
@@ Line 398: / Line 458: @@
 // exclude all other volumetric meshes or other objects - that the render pass only renders the relevant volume
-FBackFaceRenderPass1.IgnoreControl(FVolume2); // !!! only compute Volume #1
+FBackFaceRenderPass1.AllowControl(FVolume1); // !!! only compute Volume #1
 FBackFaceRenderPass1.Enabled := true;
@@ Line 411: / Line 471: @@
 // exclude all other volumetric meshes or other objects - that the render pass only renders the relevant volume
-FFrontFaceRenderPass2.IgnoreControl(FVolume1); // !!! only compute Volume #2
+FFrontFaceRenderPass2.AllowControl(FVolume2); // !!! only compute Volume #2
 FFrontFaceRenderPass2.Enabled := true;
@@ Line 420: / Line 480: @@
 // exclude all other volumetric meshes or other objects - that the render pass only renders the relevant volume
-FBackFaceRenderPass2.IgnoreControl(FVolume1); // !!! only compute Volume #2
+FBackFaceRenderPass2.AllowControl(FVolume2); // !!! only compute Volume #2
 FBackFaceRenderPass2.Enabled := true;