CPU Ray Tracing Renderer

This renderer is based on the template project of Dr. Jacco Bikker. By extending the template, the following features are developed:

• Whitted Style ray tracer
• Path tracer
• acceleration structures
  • BVH (with SAH)
  • Grid
  • KDTree
  • TLAS
• .obj model loading
• material
• texture loading & mapping
• skybox
• instruments (only available for whitted style ray tracer)
• scene file loading

Known issues that can be improved

• implement enhanced version of path tracer with more rendering features
• unbind triangle data with acceleration structures so that they can share mesh memory

IDE

Visual Studio 2022

Whitted Style Ray Tracer

Path Tracer

How to run

Open tmpl_2022-rt.sln with Visual Studio. Select a project (either WhittedStyle or PathTracer). Build.

Inspect traversal

Toggle Inspect Traversal checkbox in the panel will turn into traversal debug mode.

How to configure

Aceleration struture

There are several acceleration structure available. To support both pure acceleration structure and top level assceleration strcture, there are two type of scene. To switch between different scenes, in renderer.h, replace the scene class to either TLASFileScene or FileScene.

The first one is FileScene class, which supports adding all triangles into a single acceleration structure. In file_scene.h, there are three definitions: USE_BVH, USE_Grid, and USE_KDTree. Uncomment one of them, then the FileScene class will load the scene in certain acceleration structure.

The second is TLASFileScene class, which supports each model as an acceleation structure. A top-level acceleration structures will includes all of them. In tlas_fil_scene.h, there are three definitions: TLAS_USE_BVH, TLAS_USE_Grid, and TLAS_USE_KDTree. Uncomment one of them, then the FileScene class will load the scene in certain acceleration structure.

For configuring BVH, in bvh.h or tlas_bvh.h, there is a definition called SAH. Uncomment it will enable SAH for finding spliting planes for BVH.

Scene

There are several scenes available in assets folder. In renderer.h, the user can set the path to the scene file and start the program. The scene will be loaded automatically. A scene template looks like the following

<?xml version="1.0" encoding="UTF-8"?>
<scene>
    <!-- Scene Information -->
    <scene_name>wok scene</scene_name>
	<light_position>
		<x>0.0</x>
		<y>3.0</y>
		<z>2.0</z>
	</light_position>
    <skydome_location>../assets/industrial_sunset_puresky_4k.hdr</skydome_location>

    <!-- Object List -->
    <objects>
        <!-- Object 1 -->
        <object>
            <model_location>../assets/wok.obj</model_location>
            <material_idx>0</material_idx>
            <position>
                <x>-1.0</x>
                <y>-0.5</y>
                <z>-1.0</z>
            </position>
            <rotation>
                <x>0.0</x>
                <y>0.0</y>
                <z>0.0</z>
            </rotation>
            <scale>
                <x>0.5</x>
                <y>0.5</y>
                <z>0.5</z>
            </scale>
        </object>

        <!-- Add more objects as needed -->
    </objects>
    <materials>
		<!-- Material 0 -->
		<material>
			<reflectivity>1.0</reflectivity>
			<refractivity>0.0</refractivity>
			<absorption>
                <x>0.0</x>
                <y>0.0</y>
                <z>0.0</z>
            </absorption>
			<texture_location></texture_location>
		</material>
		<material>
			<reflectivity>0.0</reflectivity>
			<refractivity>0.0</refractivity>
			<absorption>
                <x>0.0</x>
                <y>0.0</y>
                <z>0.0</z>
            </absorption>
			<texture_location>../assets/textures/T_Trim_01_BaseColor.png</texture_location>
		</material>
	</materials>
</scene>

Original README.md from template

This template is intended for students of Utrecht University.

Please refer to "_ getting started.pdf" for instructions.

Code is fully public domain. Use as you please.

Contact me at [email protected].