Brecht Van Lommel
1b4961b318
Ref T84819 Build System ============ This is an API breaking new version, and the updated code only builds with OpenColorIO 2.0 and later. Adding backwards compatibility was too complicated. * Tinyxml was replaced with Expat, adding a new dependency. * Yaml-cpp is now built as a dependency on Unix, as was already done on Windows. * Removed currently unused LCMS code. * Pystring remains built as part of OCIO itself, since it has no good build system. * Linux and macOS check for the OpenColorIO verison, and disable it if too old. Ref D10270 Processors and Transforms ========================= CPU processors now need to be created to do CPU processing. These are cached internally, but the cache lookup is not fast enough to execute per pixel or texture sample, so for performance these are now also exposed in the C API. The C API for transforms will no longer be needed afer all changes, so remove it to simplify the API and fallback implementation. Ref D10271 Display Transforms ================== Needs a bit more manual work constructing the transform. LegacyViewingPipeline could also have been used, but isn't really any simpler and since it's legacy we better not rely on it. We moved more logic into the opencolorio module, to simplify the API. There is no need to wrap a dozen functions just to be able to do this in C rather than C++. It's also tightly coupled to the GPU shader logic, and so should be in the same module. Ref D10271 GPU Display Shader ================== To avoid baking exposure and gamma into the GLSL shader and requiring slow recompiles when tweaking, we manually apply them in the shader. This leads to some logic duplicaton between the CPU and GPU display processor, but it seems unavoidable. Caching was also changed. Previously this was done both on the imbuf and opencolorio module levels. Now it's all done in the opencolorio module by simply matching color space names. We no longer use cacheIDs from OpenColorIO since computing them is expensive, and they are unlikely to match now that more is baked into the shader code. Shaders can now use multiple 2D textures, 3D textures and uniforms, rather than a single 3D texture. So allocating and binding those adds some code. Color space conversions for blending with overlays is now hardcoded in the shader. This was using harcoded numbers anyway, if this every becomes a general OpenColorIO transform it can be changed, but for now there is no point to add code complexity. Ref D10273 CIE XYZ ======= We need standard CIE XYZ values for rendering effects like blackbody emission. The relation to the scene linear role is based on OpenColorIO configuration. In OpenColorIO 2.0 configs roles can no longer have the same name as color spaces, which means our XYZ role and colorspace in the configuration give an error. Instead use the new standard aces_interchange role, which relates scene linear to a known scene referred color space. Compatibility with the old XYZ role is preserved, if the configuration file has no conflicting names. Also includes a non-functional change to the configuraton file to use an XYZ-to-ACES matrix instead of REC709-to-ACES, makes debugging a little easier since the matrix is the same one we have in the code now and that is also found easily in the ACES specs. Ref D10274
The following 4 steps to adding a new image format to blender, its probably easiest to look at the png code for a clean clear example, animation formats are a bit more complicated but very similar: Step 1: create a new file named after the format for example lets say we were creating an openexr read/writer use openexr.c It should contain functions to match the following prototypes: struct ImBuf *imb_loadopenexr(unsigned char *mem,int size,int flags); /* Use one of the following depending on what's easier for your file format */ short imb_saveopenexr(struct ImBuf *ibuf, FILE myfile, int flags); short imb_saveopenexr(struct ImBuf *ibuf, char *myfile, int flags); /* Used to test if its the correct format int IMB_is_openexr(void *buf); Step 2: Add your hooks to read and write the image format these go in writeimage.c and readimage.c just look at how the others are done Step 3: Add in IS_openexr to blender/source/blender/imbuf/IMB_imbuf_types.h Add in R_openexr to source/blender/makesdna/DNA_scene_types.h Step 4: Add your hooks to the gui. source/blender/src/buttons_scene.c source/blender/src/toets.c source/blender/src/writeimage.c Step 5: edit the following files: blender/source/blender/imbuf/intern/util.c blender/source/blender/src/filesel.c blender/source/blender/src/screendump.c and add your extension so that your format gets recognized in the thumbnails. Step 6: Alter the build process: For cmake you need to edit blender/source/blender/imbuf/CMakeLists.txt and add in your additional files to source_files. If you have any external library info you will also need to add that to the various build processes. Step 7: Its also good to add your image format to: makepicstring in blender/source/blender/blenkernel/intern/image.c