Models (The Chickadee Game Toolkit)

From 0e699be281c8dea53e589e08a5831837e0eae7ea Mon Sep 17 00:00:00 2001 From: David Thompson Date: Thu, 7 Oct 2021 20:17:50 -0400 Subject: Updates for Chickadee 0.8.0 and Guile-SDL2 0.7.0. --- manuals/chickadee/Models.html | 167 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 167 insertions(+) create mode 100644 manuals/chickadee/Models.html (limited to 'manuals/chickadee/Models.html') diff --git a/manuals/chickadee/Models.html b/manuals/chickadee/Models.html new file mode 100644 index 0000000..3a1a6d6 --- /dev/null +++ b/manuals/chickadee/Models.html @@ -0,0 +1,167 @@ + + + + + + +Models (The Chickadee Game Toolkit) + + + + + + + + + + + + + + + + + + + + +

5.3.8 Models

+ +

Disclaimer: Chickadee is alpha software, but 3D model support is +even more alpha than that. There are many missing features in both +the model loading and rendering components, so set your expectations +accordingly! +

The (chickadee graphics model) module provides procedures to +load and render 3D models in the classic OBJ and more modern glTF 2.0 +formats. +

Here’s some basic boilerplate to render a 3D model: +

(use-modules (chickadee graphics light)
+             (chickadee graphics model)
+             (chickadee graphics skybox))
+
+(define model (load-gltf "Suzanne.gltf"))
+(define camera-position (vec3 0.0 0.0 3.0))
+(define world (make-identity-matrix4))
+(define view (look-at camera-position (vec3 0.0 0.0 0.0) (vec3 0.0 1.0 0.0)))
+(define projection (perspective-projection (/ pi 3.0) (/ 4.0 3.0) 0.1 5.0))
+
+(define (draw alpha)
+  (with-projection projection
+    (draw-model model world view camera-position
+

+ +

Procedure: load-obj file-name

Load the OBJ formatted model in file-name and return a 3D model +object. +

OBJ models are rendered using a Phong lighting model, which is a +work-in-progress. +

+ +

Procedure: load-gltf file-name

Load the glTF 2.0 formatted model in file-name and return a 3D +model object. +

glTF models are rendered using a physically based lighting model, +which is currently a stub to be implemented later. +

+ +

Procedure: model? obj: Return #t if obj is a 3D model. +

+ +

Procedure: draw-model model [#:model-matrix] [#:view-matrix] [#:camera-position (vec3 0 0 0)] [#:skybox] [#:lights '()]: +
Render model with the transformation matrices model-matrix +and view-matrix applied. camera-position is the world +position of the camera, for correct specular lighting calculations. +skybox is used to apply ambient lighting to the model. +lights contains all of the dynamic lights (see Lights) that +should have an effect on the model. +

+ +

Models are composed of simpler data types: meshes, primitives, and +materials. Let’s start with materials. A material controls the +appearance of a 3D object. Is the object a rough stone? Or maybe a +smooth metal? Materials control all of this and more. +

There are two types of materials in Chickadee: Phong and PBR. +

+ + + + + + -- cgit v1.2.3